EMI calculator — monthly instalment, interest and amortisation

An EMI is a fixed payment that clears both the interest accrued that month and part of the principal. Early instalments are almost entirely interest — which is why a five-year-old home loan that "you have paid ₹20 lakh on" can still owe nearly the original amount.

Tenure changes cost far more than most borrowers expect. Stretching a ₹40 lakh loan from 20 to 30 years cuts the monthly payment by about a quarter but adds roughly ₹25 lakh of total interest.

Comparing a 0.25% rate difference on a twenty-year loan is worth real money — often several months of salary — and takes ten seconds to check.

Calculators are the tools people return to — a loan decision this month, a tax check at year end, a BMI reading at a clinic visit. Reaching for a page that uploads nothing and logs nothing makes the return visit a comfortable one.

Every calculation runs in your browser as you type. There is no request in flight, so there is no privacy-policy asterisk to read: the salary, the loan amount, the medical figures and the dates you enter are never transmitted.

Results are shown with the working rather than as a bare number. That matters when a loan officer, a school form or a tax portal wants the figure to be justifiable, and it matters more when the figure is one you are going to argue with.

The emi calculator on this page is deliberately narrow: it answers one question, states the assumptions beside the answer, and does not ask for an email or an account first. That is the whole design — a calculator you can open, use and close without leaving anything of yourself behind.

The figure that matters is often not the one you asked for. On a loan, the monthly instalment is fixed by your cash flow while the total interest is what changes with the tenure; on a tax computation, the useful output is the difference between two regimes rather than one regime’s liability; on a retirement projection, the assumption that does the most damage is a return figure that is one percentage point too optimistic over thirty years.

The numbers you type into a calculator are among the most sensitive figures in your life: income, loans, outstanding balances, medical measurements, in some cases a diagnosis. That is the strongest argument for a calculator that runs entirely in the tab. Close this page and the numbers are gone from memory, because there was nowhere else for them to go.

Accepted inputs are PDF files up to 50 MB. SVG, HTML and other script-bearing formats are refused outright rather than sanitised, because a file that can execute code has no business being re-encoded — and an upload field that accepts one is a security hole rather than a feature. The tool works on one file at a time, which keeps the result unambiguous.

EMI is computed with the standard reducing-balance annuity formula: E = P × r × (1 + r)^n / ((1 + r)^n − 1), where r is the monthly rate (annual ÷ 12 ÷ 100) and n is the number of monthly instalments. The amortisation schedule is then generated iteratively — interest first, remainder to principal — because floating-point rounding accumulates and the closing balance must be reconciled to zero. The arithmetic follows the published formulas rather than approximations: loan instalments use the standard reducing-balance annuity formula; recurring and fixed deposits compound at the frequency the instrument specifies; tax and slab figures are applied in the order the statute defines, including surcharge and cess where relevant; age is computed on the calendar by borrowing months the way an eligibility clause does, not by dividing total days. All of it is evaluated in your browser with double-precision floating point, and each result is rounded only for display, which is why the figure you see and the figure you recompute agree to the rupee. The calculation runs locally in your browser. The page or its code may still require a connection to load, and offline use is not guaranteed. Review the assumptions and independently verify important decisions.