Savings Growth Calculator

See what a starting pot plus a regular monthly contribution grows into with compound interest.

Illustrative estimates with monthly compounding and contributions added at month end. Rates change and tax may apply above your Personal Savings Allowance — check with your provider.

How compound interest works

Interest is added to your balance, and next month you earn interest on that interest too. Over years, the curve bends upward: the longer the money stays put, the more the growth comes from compounding rather than contributions.

This calculator compounds monthly at the annual rate you enter divided by twelve, which closely matches how most UK easy-access and regular-saver accounts quote AER.