How ByeToEMI calculates

All loans are treated as monthly reducing-balance loans: EMI = P × r × (1+r)^n / ((1+r)^n − 1), where P is the principal, r is the monthly rate (annual rate ÷ 12 ÷ 100) and n is the number of monthly instalments.

At a 0% rate the formula is undefined, so we use P ÷ n instead. Tenure is capped at 600 months and the interest rate at 50% per year; anything outside those ranges is rejected with an inline error rather than calculated.

• Each month, interest = outstanding balance × monthly rate.
• The principal component is the instalment minus that interest.
• Extra monthly amounts, part payments and lump sums reduce the principal in the month they are paid, after that month's instalment.
• An annual EMI increase is applied on each anniversary of the first EMI — months 13, 25, 37 and so on.
• The final instalment is trimmed to the exact remaining balance, so the schedule ends at ₹0 with no stray rupee left over or overpaid.
• If the instalment can never cover the monthly interest, we flag the scenario as impossible instead of producing a growing balance.

Every summary figure — total interest, total payment, closing month — is the sum of the same schedule rows you can download as CSV, so the numbers always reconcile.

A transfer is modelled as a rate change from a chosen month, applied to the balance outstanding at that point. Two modes are offered:

• Keep current EMI — the instalment is unchanged, so the loan closes earlier.
• Reduce EMI — the instalment is recalculated over the remaining tenure at the new rate, keeping the original end date.

Processing fees and other transfer expenses are counted as costs in the total paid and in the net saving. They are never added to the principal, and they never earn interest. Break-even is the first month after the transfer at which cumulative interest saved covers those charges.

• Month 0 is today; the first payment happens in month 1. Each cycle we add one month of interest, make every required EMI, then send the extra amount to the current target loan.
• Avalanche targets the highest annual interest rate, snowball the smallest outstanding balance, and cards-first every credit card before term loans. Ties are broken by rate, then by balance.
• When a loan closes, its EMI is redirected to the next target from the following month — your total monthly outflow stays the same until you are debt-free.
• Credit card dues are modelled as a fixed monthly repayment plan, either derived from a payoff tenure you choose or from an amount you enter. Revolving minimum-due behaviour, cash-advance charges and fees are not modelled.
• Baseline means every loan runs to its original end date with no extra payment; savings are the difference between that baseline and the chosen strategy.

Internally we keep full floating-point precision. Rounding to whole rupees happens only when a number is displayed or exported. That is why your lender's statement may differ by a few rupees a month: lenders round the EMI itself, may compute interest on a daily basis, and apply payments on specific dates.

• GST on fees, late-payment penalties, cheque bounce charges and insurance premiums are treated as separate costs you enter, not as part of the principal.
• Floating-rate movements are never predicted; a rate stays fixed unless you model a change.
• Moratorium periods, staged disbursals, overdraft and cash-credit facilities are outside the scope of an EMI schedule.
• Tax deductions such as Section 24, 80C or 80E are not applied to the figures.

The engine is plain TypeScript running in your browser. Nothing you type is sent to a server, and the site works without an account. Shared links carry only the loan numbers you entered.