About this tool
Work out simple (non-compounded) interest using the classic formula interest = principal × rate × time, then see the final amount. Everything is calculated live in your browser.
Frequently asked questions
How is simple interest calculated?
It uses interest = principal × (annual rate ÷ 100) × time in years, so the interest does not earn interest itself.
How does it differ from compound interest?
Simple interest is charged only on the original principal, while compound interest is charged on the principal plus previously accrued interest, so compound grows faster over time.