Free Compound Interest Calculator

Compound interest is the engine behind almost every long-term savings plan — interest earning interest on itself. This free calculator shows you exactly how your money could grow over time, with a year-by-year breakdown. No sign-up, no fees, just math.

Why compounding beats saving alone

If you invest $200 a month for 20 years at a 7% average annual return, you’ll have put in $48,000 — but your balance can be close to double that. The extra comes from growth compounding on growth, which accelerates the longer you stay invested.