Calculate simple and compound interest online. Understand the power of compounding with flexible frequencies.
Evaluating loan offers or interest payouts on savings? Our online Interest Calculator lets you compare both simple interest and compound interest returns side-by-side, helping you make informed financial decisions.
Calculate total interest earned, principal splits, and maturity amounts for multiple compounding periods (monthly, quarterly, half-yearly, annually) instantly.
| Interest Type | Formula | Compounding effect | Best Used For |
|---|---|---|---|
| Simple Interest (SI) | SI = (P * R * T) / 100 | Interest calculated only on principal | Short-term loans & government bonds |
| Compound Interest (CI) | A = P * (1 + r/n)^(n*t) | Interest calculated on principal + accumulated interest | Fixed deposits, savings accounts & mutual funds |
| Maturity Amount (SI) | A = P + SI | Linear growth over time | Simple retail lending |
Simple interest is calculated only on the initial principal amount. Compound interest is calculated on the initial principal and also on the interest accumulated over previous periods ('interest on interest').
The compound interest maturity amount formula is: `A = P * (1 + r/n)^(n*t)`, where P is principal, r is annual rate, n is compounding frequency per year, and t is tenure in years.
More frequent compounding periods (e.g. monthly vs annually) yield higher interest returns over the same tenure, as interest is added back to the principal sooner.
It is a quick formula to find when your money doubles: `Years to Double = 72 / Interest Rate` (e.g. at 8% interest, it takes approx 9 years to double).
Absolute interest is the net interest amount calculated by subtracting the principal amount from the total maturity amount.
Yes. You can enter decimal values for interest rates (e.g. 7.25%) and tenure (e.g. 2.5 years).
Bank Fixed Deposits (FDs) in India typically use compound interest, compounded on a quarterly basis.
Home loans use reducing balance interest, where interest is calculated monthly on the remaining principal balance, which behaves similarly to compounding interest.
Yes, our interest calculator is 100% free with no registration or limits.
No, all inputs are processed locally in your browser memory, keeping your sessions private.