1. Loan amount — the sum sanctioned (processing fees are often deducted from it, so you may receive slightly less).
2. Annual interest rate — the reducing-balance rate from the sanction letter or key-fact statement, not a 'flat' rate.
3. Loan tenure — in years; personal loans typically run 1 to 5 years.

You see the monthly EMI, total interest, total repayment and interest as a percentage of the loan, plus the amortisation table.

Rate matters more for a personal loan than for a home loan because rates are higher and tenures shorter: on ₹5 lakh over 3 years, moving from 12% to 16% raises the EMI from about ₹16,607 to ₹17,579 and total interest from about ₹97,900 to ₹1,32,800. Stretching the tenure from 3 to 5 years at 12% lowers the EMI but raises total interest from about ₹97,900 to ₹1,67,300 — roughly 70% more. If a lender quotes a flat rate, convert it first — see how loan interest works.

Personal loans are unsecured, so lenders price in more risk and rates are typically higher than home or car loans. They usually have short tenures (a few years) and fixed rates, so the EMI stays constant. Interest is still charged on the reducing balance.

Some lenders quote a 'flat' rate, which is charged on the original amount for the whole tenure and is not comparable to a reducing-balance rate. A flat rate always costs more than the same number quoted as a reducing rate. This calculator uses the reducing-balance method; ask your lender which one they quote.

EMI = P × r × (1 + r)n / [ (1 + r)n − 1 ] with r the monthly rate and n the tenure in months. For ₹5 lakh at 14% over 3 years, r = 0.011667 and n = 36, giving an EMI of about ₹17,089. Because personal loans are short and expensive, prepaying even a few EMIs early saves a visible share of the interest — test it with the Loan Prepayment calculator, after checking the foreclosure charge.