SIP, EMI, XIRR, retirement, inflation and fifteen more — each one showing the formula it used and the assumptions it made, so you can check the answer rather than trust it.
What a fixed monthly investment grows to at a constant assumed return.
Formula FV = P × [((1+i)n − 1) ÷ i] × (1+i) — the annuity-due form, i = annual rate ÷ 12, n = months
Each instalment is a separate lumpsum that compounds for a different length of time — the first one for the whole period, the last one for a month. The formula above is just that sum written in closed form.
The trailing × (1+i) is the part most pages leave unexplained. It assumes the instalment goes in at the start of each month, so every instalment earns one extra month of growth. That is what a real SIP does: the money leaves your bank on the mandate date and units are allotted on that day's NAV. Drop the term and you get the ordinary-annuity value, shown above as the fourth output. On a ₹10,000 SIP over 15 years at 12% the gap is ₹49,958 — exactly five months' instalments, and not a rounding difference.
What this assumes a constant return every single month, no exit load, no securities transaction tax, no capital-gains tax on redemption, and a return figure you have already netted of the scheme's expense ratio. Real returns are not constant; this tells you what a constant one would have produced.
Background reading: What a SIP actually is · SIP against lumpsum, honestly · Why a SIP's return is XIRR, not CAGR
What a single investment grows to, and what that is worth in today’s money.
Formula FV = P × (1+r)n. In today’s rupees: FV ÷ (1+f)n, which is identical to P × (1+rreal)n where rreal = (1+r)÷(1+f) − 1
Compounding annually is the whole of the first line. The second line is the part worth having: money in fifteen years is not the same unit of account as money today, and a future value quoted without that caveat overstates what it buys.
Note that the two ways of getting the real figure agree exactly — deflating the final value, or compounding at the real rate from the start. That identity is why real return is a ratio, not a difference. At 12% and 6% the ratio gives 5.66% and the subtraction gives 6%. Over 15 years that 0.34 percentage point gap compounds into roughly 5% of the answer.
What this assumes a constant nominal return and a constant inflation rate, both compounded once a year, no tax on redemption, and no charges. Your own inflation rate is not CPI — it is whatever your spending basket does.
Background reading: SIP against lumpsum, honestly · What inflation does to a corpus · Time value of money
How long a corpus lasts if you withdraw a fixed amount every month.
Formula Month by month: balance × (1+i), then subtract the withdrawal. Depletion month n = ln[W ÷ (W − C·i)] ÷ ln(1+i), and the corpus never depletes when W ≤ C·i
A systematic withdrawal plan is an ordinary annuity run backwards. Growth is credited, the withdrawal is taken, and the smaller balance grows next month — which is why a withdrawal a few thousand rupees above the break-even point does not shorten the life of the corpus a little. It shortens it a lot.
The break-even line, C × i, is the one number to look at first. Below it the corpus grows regardless; above it the depletion date moves in fast. And note what "leaves the capital untouched" means here: untouched in rupees. A corpus that is the same size in twenty years has lost most of its purchasing power. Use the inflation calculator to see by how much.
What this assumes a constant return, withdrawal taken at the end of each month after that month's growth, a withdrawal that never rises with inflation, and no tax or exit load on the units redeemed. Capital-gains tax on an SWP is real and is not modelled here.
Background reading: How an SWP works · Where retirement income comes from · Inflation after you stop earning
Moving a lumpsum into a target fund in monthly slices, with both sides earning.
Formula Simulated month by month: source × (1+is) − transfer; target × (1+it) + transfer. Both monthly rates are the annual figure ÷ 12
A systematic transfer plan is a SIP whose funding account happens to be another fund rather than your bank. The arithmetic has to track both sides, because the money still waiting in the source is earning something — that is the point of parking it in a liquid or ultra-short fund rather than a savings account.
What the two-sided view makes visible is the cost of staggering. Compare the combined figure against the same lumpsum invested in the target fund on day one at the target rate. When the target return is higher than the source return — the usual reason for doing this at all — the staggered route ends behind. What you bought with that difference is a smaller loss if the target falls early. Averaging reduces the damage from bad timing; it does not create return.
What this assumes constant returns on both sides, transfers at the end of each month, and no exit load or capital-gains tax on the units redeemed from the source. In reality every STP instalment out of a debt fund is a redemption and is taxed as one.
Background reading: SIP against lumpsum, honestly · What debt funds actually hold · What a SIP actually is
The monthly instalment on a loan, and what the loan costs in total.
Formula EMI = P · r · (1+r)n ÷ [(1+r)n − 1], where r is the MONTHLY rate (annual ÷ 12) and n is the number of months
An EMI is the constant payment that exactly clears the loan over n months. Each payment covers that month's interest on the outstanding balance first; whatever is left reduces the principal. Early on almost all of it is interest, because the balance is large.
The commonest error in this formula is feeding it the annual rate. At 8.5% over 20 years, using 0.085 instead of 0.0070833 as the monthly rate returns an EMI of ₹4.25 lakh against the correct ₹43,391 — about ten times too high. The second commonest is reading the interest total as a measure of how bad the loan is — a longer tenure always shows more total interest and a smaller EMI, and which of those matters depends on whether the constraint is monthly cash or lifetime cost.
What this assumes a fixed interest rate for the entire tenure, no prepayment, no processing fee, no insurance bundled into the loan, and every instalment paid on time. A floating-rate home loan will not follow this schedule for long.
Background reading: How an EMI is built · Home loans, end to end · What lenders will lend you
The corpus that funds an inflation-linked income for life, and the SIP that builds it.
Formula Corpus = Eret × [1 − (1+ir)−N] ÷ ir × (1+ir), where ir is the real monthly rate from (1+post)÷(1+inflation) − 1, and Eret = today’s expenses × (1+inflation)Y
Two horizons run here and they must not be confused. Between now and retirement, expenses inflate and savings compound at the pre-retirement rate. After retirement, the corpus keeps earning while you draw an income that itself has to keep rising with prices — a fixed withdrawal is a falling standard of living.
Discounting that rising stream at the real rate is the whole trick. Using the nominal post-retirement return instead is the standard mistake and it understates the corpus badly: at 8% nominal and 6% inflation the real rate is 1.89%, and a 25-year income stream discounted at 1.89% needs about 84% more capital than the same stream discounted at 8% — the annuity factor goes from 130 months of income to 239. Every output above is labelled today's rupees or future rupees, because a corpus figure without that label is meaningless.
What this assumes constant returns and constant inflation, expenses that track your assumed inflation rate exactly, withdrawals at the start of each month, no pension or rental income, no lump medical costs, no tax on withdrawals, and nothing left behind at the end — the corpus is drawn to zero at the final age.
Background reading: Working out a retirement corpus · How much is enough · Inflation after you stop earning
What a price becomes, what money loses, and the real return on top.
Formula Future cost = A × (1+f)n. Today’s worth of future money = A ÷ (1+f)n. Real return = (1+r) ÷ (1+f) − 1
Inflation is the same compounding as a return, pointed the other way. Six percent for twenty years is not 120% — it is a multiplier of 3.21, so a bill that is ₹1 lakh today is ₹3.21 lakh then.
The real-return line is the one worth memorising. Real return is a ratio, not a subtraction. Ten percent against six percent inflation is 3.77% real, not 4%. The gap looks trivial and is not: over twenty years it is about 4.5% of the final corpus. The error is systematic and always in the same direction — subtraction always flatters the answer.
What this assumes a single constant inflation rate applied to everything. Your actual inflation rate depends on what you buy: school fees and medical care in India have run well above headline CPI for years, and electronics below it.
Background reading: What inflation is and how it is measured · The inflation you cause yourself · Time value of money
The single annual rate that turns one value into another over a period.
Formula CAGR = (End ÷ Start)1÷n − 1. Undefined when Start ≤ 0, and undefined for a negative End
CAGR is not an average of the yearly returns. It is the one constant rate that, compounded over the period, connects the two endpoints — so it says nothing at all about the path. A fund that went up 60% and then down 25% and a fund that crept up steadily can share a CAGR and be completely different things to hold.
Two limits worth stating. CAGR needs exactly two cashflows, so it is the wrong measure for anything you added to or withdrew from along the way — that is XIRR's job. And it is genuinely undefined for a zero or negative start: a fractional root of a negative ratio is not a real number, and no arithmetic rescues it. Pages that return a figure there are returning nonsense.
What this assumes exactly two cashflows — one in at the start, one out at the end. Any deposit or withdrawal in between makes this figure wrong, not merely imprecise.
Background reading: XIRR against CAGR · The rule of 72 · Risk and return
The annualised return on cashflows that land on irregular dates — solved, not approximated.
Formula Solve Σ CFk ÷ (1+r)(dk − d0)÷365 = 0 for r. Solved here by bisection over [−99.9999%, upward], 300 iterations — the same actual/365 day count Excel’s XIRR uses
Every cashflow gets weighted by how long it was actually invested. An amount put in three months before the end contributes almost nothing to the annualised figure; the first instalment carries most of it. That weighting is why a SIP's return is XIRR and never CAGR — CAGR assumes one entry and one exit, and a SIP has as many entries as it has instalments.
There is no closed form. The equation is a polynomial of high degree in (1+r) and has to be solved numerically, which is what the bisection above does: bracket a sign change, halve the interval 300 times, and the answer is exact to far more decimals than the inputs deserve. Bisection rather than Newton because Newton can walk off a flat region and fail to converge on lumpy real cashflows, and a wrong return is worse than a slow one.
One caveat that is inherent to the measure, not to this implementation: cashflow streams that change sign more than once can admit more than one mathematically valid rate. This returns the one found in the bracket that contains a sign change. Ordinary investment patterns — money in, then money out — have exactly one.
What this assumes actual/365 day counting, cashflows on the dates you give, and that any closing value is entered as a positive cashflow on today’s date. It does not know about tax, and it does not verify that your dates are real.
Background reading: XIRR against CAGR · What a SIP actually is · Risk measures worth reading
What a target costs by the time you get there, and the monthly investment it takes.
Formula Future cost = target × (1+f)n when stated in today’s rupees. Shortfall = future cost − existing × (1+r)n. SIP = shortfall ÷ {[((1+i)n×12 − 1) ÷ i] × (1+i)}
The dropdown is the point of this calculator. Almost every goal is quoted in today's prices — a car "costs ₹15 lakh", a course "costs ₹20 lakh" — and the amount you have to arrive with is the inflated one. Planning to today's number and reaching the date is the most common way a goal quietly fails.
The second half nets off what you already hold, grown at the same assumed return. That matters more than it looks: money already invested has the full period to compound, so at 11% over ten years a rupee already invested replaces about ₹1.55 of instalments spread across the ten years. If the SIP figure looks impossible, the lever with the most leverage is usually the horizon, not the rate.
What this assumes a constant return, a constant inflation rate, contributions at the start of each month, and no tax on redemption at the end. It also assumes you keep contributing every month for the whole period.
Background reading: Investing against goals rather than products · What financial planning covers · What inflation does to a target
How large a cash buffer your own expenses imply, and how long it takes to build.
Formula Target = essential monthly expenses × months of cover. Time to fill = shortfall ÷ monthly saving
Deliberately the simplest calculation on this page, and deliberately not compounded. An emergency fund's job is to be available on the day something happens, which rules out anything whose value can be down when you need it. Money that has to be there in full on an unknown date should not be earning a return that requires time to materialise.
The input that decides the answer is what counts as an essential expense. People size the fund against their salary, or against total spending including holidays, and end up with a number that is either uselessly small or so large it never gets built. The figure that matters is what you would still have to pay in a month with no income — rent, EMIs, food, school fees, insurance premiums, medicines. An EMI does not pause because your income did.
What this assumes no return on the fund and no inflation over the building period — both small over the year or two this usually takes, and both erring towards a slightly larger buffer. Your expenses are assumed steady.
Background reading: Building an emergency fund · Where to keep it · Planning for a medical emergency
Everything you own, less everything you owe — the one number that nets off.
Formula Net worth = Σ assets − Σ liabilities. The second line removes the home and its loan from both sides
Net worth is a snapshot of position, not of income. Two people earning the same salary can sit thirty lakh apart on this line, and the direction it moves year to year says more than any single year's return does.
The split matters more than the total. A home you live in is an asset you cannot spend — selling it means buying or renting another one — so the line that excludes the property and its loan is usually the more informative of the two. Value property at what it would actually fetch, not at the circle rate or the price of the last flat sold in the building; an inflated property figure is the most common way this number flatters.
What this assumes current market values, no tax on any unrealised gain, and no illiquidity discount — property in particular is entered at a price you have not been offered.
Background reading: What net worth measures · Which borrowing is which · What financial planning covers
How far your portfolio has drifted from the split you chose, in rupees.
Formula Drift = total × target% − current holding, per sleeve. A positive figure is money to add, a negative figure is money to take out
Nothing here decides your split — you type the target in, and the arithmetic only says how far the market has moved you from it. That distinction is the whole point: the allocation is a judgement about your own horizon and tolerance, and the rebalancing is arithmetic.
What makes drift worth measuring is that it is self-reinforcing in exactly the wrong direction. A good run in equities raises the equity share, so the portfolio carries the most equity risk right after the period that made equities look safest, and the least right after they looked worst. Rebalancing is the mechanical answer to that, and its cost is real — you sell what has been working, and in a taxable account you crystallise gains to do it.
What this assumes current market values, and that the three sleeves cover everything you count as your portfolio. It ignores capital-gains tax and exit loads on the switching, which can be the deciding cost on a small drift.
Background reading: What asset allocation does · How rebalancing works · Rebalancing on bands rather than dates
A multi-year course, escalated at education inflation and discounted back to the start date.
Formula Corpus = Σk=0..D−1 C × (1+e)Y+k ÷ (1+r)k — each year’s fee inflated to when it is paid, then discounted back to the start of the course
A degree is not one payment, and treating it as one is why education planning usually comes up short. Each year's fee inflates for longer than the last, and the money for the later years sits invested while the earlier years are being paid — so the corpus needed on day one is less than the sum of the inflated fees, but a great deal more than four times today's fee.
The two rates in that sum pull against each other, and which one is larger decides the shape of the answer. Education inflation running above your assumed return is the case that hurts: the later years then cost more, in present-value terms, than the first, and the total climbs faster than the horizon does. Enter the two honestly and the calculator will tell you plainly whether you are in that case.
What this assumes fees rising at your assumed education inflation rate, a constant return on the unspent balance, contributions at the start of each month, and the whole cost met from this corpus — no scholarship, no education loan, no family contribution.
Background reading: Money questions parents actually face · How education loans work · Investing against goals rather than products
A single dated expense, inflated to the date and worked back to a monthly figure.
Formula Future cost = C × (1+f)n; shortfall = future cost − existing × (1+r)n; the SIP is the annuity-due instalment that reaches the shortfall
Structurally the same problem as any dated goal, with one wrinkle worth naming: a wedding budget is elastic in a way a college fee is not, and the figure people enter is usually the one they hope to spend rather than the one families around them actually spend. Enter the honest number and the calculator does the rest.
The other thing this makes visible is the shortening horizon problem. As the date approaches, the same shortfall has fewer months of compounding to work with, so the required monthly figure rises much faster than the remaining time falls. Halving the horizon from eight years to four more than doubles the monthly amount. The cost of starting late is not linear.
What this assumes a constant return, a constant inflation rate, contributions at the start of each month, and no tax on redemption. Also that the expense lands as a single amount on one date.
Background reading: Money after marriage · Investing against goals rather than products · What inflation does to a target
The loan a given income supports, working back from the instalment a lender will allow.
Formula EMI room = income × FOIR − existing EMIs. Loan = EMI × [(1+r)n − 1] ÷ [r · (1+r)n] — the EMI formula solved for P, r monthly
This is the EMI calculation run backwards. A lender decides what share of your income may go to instalments, subtracts what you already owe monthly, and the loan is whatever the remainder supports at their rate over their tenure.
Two things follow that people find surprising. An existing EMI costs you far more eligibility than its own size — at 8.5% over 20 years, every ₹1,000 of existing instalment removes about ₹1.15 lakh of borrowing capacity. And the tenure is the most powerful lever in the formula, because it moves the annuity factor rather than the income: stretching 15 years to 25 raises the eligible amount by about 22%, at the cost of a great deal more total interest. Eligibility is not affordability, and the two are routinely confused.
What this assumes that the lender's FOIR is the only test applied, which it is not — credit score, employment type, age at maturity, property valuation and loan-to-value caps all bind independently. It also ignores processing fees and any insurance the lender attaches.
Background reading: How lenders decide what to lend · Home loans, end to end · What a credit score measures
The property price your income and cash support once the loan cap and buying costs are in.
Formula Two ceilings, take the lower. Income ceiling: V = (Lmax + cash) ÷ (1+c). Cash-and-LTV ceiling: V = cash ÷ (1 − LTV + c). c is one-off costs as a share of the price
Most affordability calculators answer the wrong question: they compute the loan your income supports and call it the budget. Two things break that. Stamp duty, registration and brokerage are paid on top of the price and come out of the same cash as the down payment; and the lender will only fund a fixed share of the valuation, so beyond a point more income does not help — only more cash does.
Hence two ceilings, and the answer is whichever binds first. The algebra of the second one is where the mistakes hide: your cash has to cover the price minus the loan, plus costs charged on the price, so V × (1 − LTV + c) = cash. At an 80% cap and 8% costs that is V × 0.28 — ₹25 lakh of cash supports about ₹89 lakh of property, not the ₹1.25 crore that "20% down" suggests. The output tells you which constraint is binding, because that decides whether waiting to save more would change anything.
What this assumes a fixed rate for the whole tenure, that the lender's valuation matches the price, that all your cash is available for this purchase, and that the one-off costs percentage covers everything — stamp duty alone varies by state and by the buyer's gender in several of them. No moving, interiors or furnishing costs are included.
Background reading: Home loans, end to end · How lenders decide what to lend · How an EMI is built
The instalment, and the annual rate the whole arrangement actually costs.
Formula Standard EMI on the purchase amount, then the effective cost is the rate m solving (P − fee − GST on fee) = Σ (EMI + GST on that month’s interest) ÷ (1+m)k, annualised as (1+m)12 − 1
The instalment is an ordinary EMI. What makes card EMI different is everything bolted on around it: a processing fee charged upfront, GST on that fee, and GST on every month's interest — each of which you pay and none of which appears in the quoted rate.
So the honest figure is not the quoted rate but the internal rate of return of the whole cashflow: what you effectively received on day one against what you actually pay each month. The fee is the part that bites on short tenures, because it is charged once regardless of term — a ₹199 fee on a three-month conversion is a much larger annualised cost than the same fee over eighteen months. Change the tenure above and watch the quoted rate stay still while the effective rate moves.
The same arithmetic exposes a "no cost EMI": enter the quoted rate as 0 and keep the fee, and the effective cost is still positive. If the price was also raised or a discount withheld to fund the offer, that is a further cost this calculator cannot see, because it never appears on the statement.
What this assumes interest charged on the reducing balance at the quoted rate ÷ 12, GST on interest and fee at the rate you enter, no foreclosure and no late payment. It does not model the flat-rate method some issuers use, which charges interest on the original amount throughout and costs more again.
Background reading: How credit cards work · The interest-free period, and when it ends · How an EMI is built
What compounding frequency does to the same headline rate.
Formula A = P × (1 + r÷m)m·n. Effective annual rate = (1 + r÷m)m − 1
A quoted rate is nominal until you know how often it is applied. Interest credited quarterly starts earning interest itself from the next quarter, so the same 7.5% headline is 7.71% effective quarterly and 7.76% monthly. The gap widens with the rate and is why deposits are advertised on the nominal rate and compared on the effective one.
This is also the cleanest place to see why the SIP and EMI calculators on this page divide the annual rate by 12. That is the nominal monthly convention, which every Indian lender and SIP calculator uses: 12% quoted means 1% a month, which compounds to 12.68% a year. It is a convention, not an approximation — but it means "12%" describes a slightly different thing depending on where you read it.
What this assumes a fixed rate for the whole period, interest reinvested at the same rate every time it is credited, no withdrawal, no TDS and no tax on the interest. Interest on a bank deposit is taxable at your slab rate as it accrues, which this does not deduct.
Background reading: How interest rates are quoted · The rule of 72 · Time value of money
How many years of saving it takes before a portfolio could cover your expenses.
Formula Target = annual expenses ÷ withdrawal rate. Then compound month by month at the real rate ir = [(1+r)÷(1+f) − 1] ÷ 12, contribution at the start of each month, until the balance reaches the target
Everything here is in today's rupees, which is the only way the answer means anything. Working in nominal terms produces a corpus figure that looks reachable and a target that has moved by the time you get there. Compounding at the real rate and holding the contribution constant is the same as saying your savings rise with inflation — if they do not, this is optimistic.
The withdrawal rate is the assumption that dominates everything else, and it is yours to set. Dropping from 4% to 3% raises the target corpus by a third; going to 5% cuts it by a fifth. The figure most often quoted comes from American research on 30-year retirements in American markets, and whether it transfers to Indian inflation and Indian assets is an open empirical question rather than a settled one. Try several and see how much of the answer is really an assumption.
What this deliberately does not model is the drawdown itself — whether the corpus survives depends on the order returns arrive in, not only their average, and a bad first decade with withdrawals running is a different outcome from the same average arriving in a different order.
What this assumes a constant real return with no volatility, savings that keep pace with inflation, expenses that do too, no tax on the corpus or on withdrawals, and no change in circumstances over a period that is usually measured in decades.
Background reading: Financial independence and FIRE · Retiring early in India · How much is enough
Monthly rates. Where an annual rate has to become a monthly one, it is divided by 12. That is the convention Indian SIP calculators and Indian lenders both use, and it is nominal rather than effective: 12% entered means 1% a month, which compounds to 12.68% over a year. The compound interest calculator above shows exactly what that difference is worth.
Real returns. Anywhere inflation meets a return, the real rate is (1 + nominal) ÷ (1 + inflation) − 1 — never nominal minus inflation. At 12% and 6% the two give 5.66% and 6%, and the error runs the same way every year, so it compounds. It is the single commonest mistake on Indian calculator pages.
Today’s rupees against future rupees. Any calculator that spans years says on the output label itself which of the two it is quoting. The retirement, goal, education and lumpsum calculators show both, because the corpus you need and what that corpus buys are different questions.
Instalment timing. Monthly contributions are treated as arriving at the start of the month (annuity-due), matching a real SIP mandate. Withdrawals in the SWP calculator are taken at the end of the month, after that month’s growth. Both are stated on the calculators themselves.
What none of them model. Tax, exit loads, transaction costs, and the fact that returns arrive in an order rather than as an average. A constant return is a modelling convenience, not a description of any market. Where that matters most — drawing an income from a corpus — the calculator says so.
The SIP calculator uses the annuity-due form, FV = P x [((1+i)^n - 1) / i] x (1+i), where i is the annual rate divided by 12 and n is the number of months. The trailing (1+i) assumes the instalment is invested at the start of each month, which is what a real SIP mandate does. The ordinary-annuity value, with the instalment at the month end, is shown alongside it so you can see the difference: it is one extra month of growth on every instalment, and on a long SIP it is worth several months of contributions.
CAGR connects exactly two cashflows - one amount in, one amount out - so it has no way to account for money added along the way. A SIP has as many entries as instalments, each invested for a different length of time. XIRR solves for the single annual rate at which every dated cashflow, discounted back to the first date, nets to zero. There is no closed form for it; it has to be solved numerically.
By bisection over the discount rate: bracket a sign change in the net present value function, then halve the interval 300 times. Day counting is actual/365, the same convention Excel's XIRR uses. Bisection rather than Newton's method because Newton can fail to converge on lumpy real-world cashflows, and a wrong answer would be worse than a slower one.
EMI = P x r x (1+r)^n / ((1+r)^n - 1), where P is the loan, n is the number of months, and r is the MONTHLY interest rate - the annual rate divided by 12. Feeding the annual rate into r is the commonest error and returns an instalment several times too large.
(1 + nominal) / (1 + inflation) - 1. Never nominal minus inflation. At 12% nominal and 6% inflation the real return is 5.66%, not 6%. The subtraction overstates the answer by roughly inflation multiplied by the real return, and because it is always in the same direction it compounds: over 25 years it is worth several percent of the final corpus.
Each calculator says so on the output label itself, because a corpus figure without that label means nothing. The retirement, goal, education and marriage calculators show both. The financial independence calculator works entirely in today's rupees. Where a figure is a future amount, it is marked as one.
No. Every rate field carries a note saying it is an illustrative placeholder to be replaced. FNOTrader is not a SEBI-registered investment adviser or research analyst, and nothing on this page is advice or a suggestion about what return to assume, what to hold, or what to buy. These are arithmetic tools: they compute the consequences of assumptions you supply.
All twenty are free, need no login, and run entirely in your browser. There is no network call in the page and nothing you enter is stored or sent anywhere.
Each calculator links to the Academy article that explains the idea behind it — why a SIP’s return is XIRR and not CAGR, what inflation does to a corpus, how an EMI is built, and the rest. The full library is on the blog, and the terms used across it are defined in the glossary. Traders looking for position sizing, expected value, Kelly and risk-of-ruin will find those on the trading calculators page instead — also free, also no login.