Compound Interest Calculator
See what a one-time deposit grows into when interest compounds, and how much of the final amount is interest earned.
How compounding works
Compounding is when your interest earns interest too. Your balance grows each period, and then the next period's interest is calculated on that bigger amount. Leave ₹1 lakh at 8% yearly and it becomes about ₹2.16 lakh in ten years. The longer you leave it, the steeper the growth.
More frequent compounding helps a bit for the same rate—monthly beats yearly because the interest gets added back sooner and starts earning. If you're making regular monthly deposits instead of one lump sum, try our SIP calculator.
Common questions
What's the difference between simple and compound interest?
Simple interest is calculated only on what you put in. Compound interest is calculated on what you put in plus all the interest already earned. Over time, compounding pulls way ahead.
Does how often interest is added really matter?
Yes, it makes a difference. Monthly compounding beats yearly at the same rate because interest gets added sooner and starts earning faster. The longer the time and higher the rate, the bigger this effect becomes.
What rate should I enter?
Use whatever rate your bank or investment actually offers. This tool just compounds whatever you put in, so use the real rate to get a realistic answer.