What is a compound interest calculator?
Compound interest A = P × (1 + r/n)^(n × t); simple interest SI = P × r × t ÷ 100. With compounding, interest is added to the balance and earns interest itself, so ₹50,000 at 8% for 10 years grows to about ₹1,10,982 compounded monthly, against ₹90,000 with simple interest.
Features
- Compound or simple interest
- Yearly, half-yearly, quarterly or monthly compounding
- Optional monthly addition
- Principal vs interest split
How to use the compound interest calculator
- Choose compound or simple.
- Enter the principal, yearly rate and years.
- For compound interest, pick how often it compounds and any monthly addition.
The rule of 72
Divide 72 by the yearly rate to estimate how many years money takes to double with compounding: at 8%, about 9 years; at 12%, about 6 years. It is a quick check, not an exact figure.
Frequently asked questions
What is the difference between simple and compound interest?
Simple interest is paid only on the original amount. Compound interest is also paid on interest already earned, so the balance grows faster each year.
Does more frequent compounding help?
Yes, a little: monthly compounding gives slightly more than yearly at the same rate.
Last updated 15 November 2026. Made by Criza Labs. Spotted a mistake? Tell us.
