Compound Interest Calculator
🔒 In your browserCompound interest with annual, quarterly or monthly compounding.
How it works
Calculate compound interest — interest that earns interest. Enter the principal, the annual rate, the number of years and how often it compounds.
The more often interest compounds, the more you earn — monthly beats annual for the same rate. For a flat calculation, use the Simple Interest Calculator.
🔒 Calculated entirely in your browser — nothing is uploaded.
🔒 Calculated in your browser: your loan, investment and salary figures are never uploaded. Interest, tax and salary structures vary by bank and employer, so treat the result as a close estimate and confirm exact figures with them.
About the Compound Interest Calculator
This free compound interest calculator shows how a sum grows when interest earns interest. Enter the principal, the annual rate, the number of years and how often it compounds — annually, half-yearly, quarterly or monthly — for the final amount and total interest.
It runs in your browser, with no signup.
How compound interest works
Compound interest adds each period's interest back to the balance, so the next period earns interest on a larger amount. The formula is A = P × (1 + (r ÷ n) ÷ 100)^(n × t), where P is the principal, r the annual rate, n the number of times it compounds per year and t the years. The more frequently it compounds, the more you earn at the same headline rate.
A worked example
Invest ₹1,00,000 at 10% for 5 years. Compounded annually it grows to ₹1,61,051; compounded monthly at the same 10% it reaches about ₹1,64,531. The extra ₹3,480 comes purely from compounding more often — the rate is identical.
Frequently asked questions
What is the compound interest formula?
A = P × (1 + (r ÷ n) ÷ 100)^(n × t), where P is principal, r the annual rate, n the compounding frequency per year and t the time in years. The calculator applies it for the frequency you choose.
How does compounding frequency change the result?
More frequent compounding earns more at the same rate, because interest is added to the balance sooner. Monthly beats quarterly, which beats annual.
How is this different from simple interest?
Simple interest is charged only on the original principal; compound interest is charged on principal plus accumulated interest. Use the Simple Interest Calculator for the flat version.
Can I use it for loans and investments?
Yes — the same maths applies to any amount that compounds, whether it's savings growing or a debt accruing interest.
Is my data private?
Yes — everything is calculated in your browser.