Compound Interest Calculator
Calculate interest that compounds over time.
Compound Interest
Calculate interest that compounds over time.
%
Final amount
1,103.81
- Interest earned: 103.81
How it works
Enter the principal, the annual interest rate, the number of years, and how many times per year interest compounds.
Each compounding period earns interest on the principal plus all interest already earned, not just the original principal.
Compounding frequency must be a positive whole number (e.g. 1, 4, 12, 365).
Formula
A = P(1 + r/n)^(nt)
principal (P), annual rate (r), years (t), compounds per year (n)
Worked example: 1000 at 10% compounded quarterly for 1 year earns 103.81 interest, for a final amount of 1,103.81
More examples and edge cases
- Compounding more often grows the result slightly: 1,000 at 10% for 1 year becomes 1,100.00 compounded yearly, 1,103.81 quarterly, 1,104.71 monthly and 1,105.16 daily
- Over longer periods the gap to simple interest widens: 1,000 at 5% for 10 years compounded yearly reaches 1,628.89, against 1,500.00 with simple interest