Compound interest calculator
Enter your numbers — the results update instantly.
Formula
A = P(1 + r/n)ⁿᵗ + PMT · ((1 + r/n)ⁿᵗ − 1) / (r/n)
Worked example
Given: Initial amount = 10,000; Monthly contribution = 100; Annual rate = 7 %; Years = 10
Result: Final amount = 37,405.09; Total contributed = 22,000; Interest earned = 15,405.09
How it is calculated
1. Enter the values you know. 2. The calculator converts them to base units and applies the formula. 3. The result is shown in the unit you choose.
Frequently asked questions
How do I calculate it?
Formula: A = P(1 + r/n)ⁿᵗ + PMT · ((1 + r/n)ⁿᵗ − 1) / (r/n). Given: Initial amount = 10,000; Monthly contribution = 100; Annual rate = 7 %; Years = 10. Result: Final amount = 37,405.09; Total contributed = 22,000; Interest earned = 15,405.09.
Is the calculator free and private?
Yes. It is free, needs no sign-up and runs in your browser — the numbers you type stay on your device.