Compound Interest Calculator

What is Compound Int.?

Compound interest earns interest on previously-earned interest. This calculator models growth with optional recurring contributions at daily, monthly, quarterly, or annual compounding.

How it works

We apply the compound interest formula A = P(1+r/n)^(nt) plus future value of periodic contributions. The result splits into principal, contributions, and earned interest.

1. Enter your input. Type or paste your input into the field above — the tool responds instantly.
2. Review the result. Output updates live as you type. Everything runs entirely in your browser.
3. Copy or download. Use the Copy button to grab the result, or Download to save it as a file.

Examples

Realistic sample

Type or paste any realistic input — the tool computes the result locally and instantly.

Common mistakes

Expecting a server round-trip

Nothing is uploaded — every tool in this category runs entirely in your browser.