Compound interest calculator with optional regular contributions. See how a savings account, retirement fund, or investment grows over years with monthly compounding.

Compound interest is what makes long-term saving worth it — your interest earns interest, which earns interest, etc. A $5,000 deposit at 7% annual return becomes $19,348 in 20 years (with no further deposits). Adding $200/month brings it to $124,548. The graph shows how dramatically the contribution-vs-growth ratio shifts over time.

Defaults to monthly compounding (matches most savings accounts). For something like an annuity that compounds quarterly, adjust accordingly. Inflation isn't subtracted — the result is nominal, not real.

Everything happens on your device. Close the tab and it's gone.