Financial literacy guide

Compound interest explained

Compound interest means interest is calculated on the original amount plus previously accumulated interest.

InterestCompounding

Editorial review: August 11, 2026 · Lauren M. Whitfield

Growth builds on prior growth

This is why the same rate applied over more periods can create an accelerating curve.

Rates need context

Annual percentage yield, compounding frequency, fees and taxes can change real outcomes.

Borrowing compounds too

Compounding can increase the cost of some debts as well as the growth of savings.

Examples are not forecasts

A calculator using a chosen rate illustrates mathematics; it does not promise that a financial product or investment will earn that rate.

Educational information only. Use current product terms and the rules that apply in your country. For decisions with significant financial consequences, consider an appropriately qualified professional.