Book 5 · Savings & Compound Interest

Compound Interest Calculator

A starting amount, an optional monthly top-up, and time. See the balance grow — and how much of it is growth, not your own money.

Home › Calculators › Compound Interest

Enter your numbers, then press Calculate.
From the book — Chapters 1 & 4. Compounding earns interest on the interest, so each year grows by more than the last. Split the final balance into what you put in and what growth added: over a long stretch, the growth can dwarf the contributions. (Compounded monthly; rate is a plain illustrative figure.)

Educational only — not investment advice; no product is implied. Real returns vary and aren’t guaranteed. Everything stays in your browser.