How does compounding frequency change the result?

More frequent compounding applies interest to a smaller period's rate more often, which very slightly increases the final balance compared to less frequent compounding at the same annual rate — daily compounding earns a bit more than annual compounding.

What counts as a 'period' for contributions?

A period matches the compounding frequency you choose — if you pick monthly compounding, the contribution is added once per month, right before that month's interest is applied.

Is this the same as an investment return calculator?

It's closely related — this tool assumes a fixed rate and models the effect of compounding and periodic deposits, which is the core mechanic behind savings accounts, CDs, and simplified investment projections.

Is my financial data sent anywhere?

No. All math runs locally in your browser — nothing is transmitted or stored.

COMPOUND INTEREST CALCULATOR

Project growth with compounding and contributions. Nothing leaves your browser.

Initial principal

Annual interest rate (%)

Years

Contribution per period

Compounding frequency

Final balance50,969.84

Total contributed34,000.00

Total interest earned16,969.84

How to calculate compound interest

1
Enter your initial principal and the annual interest rate.
2
Set the number of years and, optionally, a regular contribution per period.
3
Pick a compounding frequency: annually, semi-annually, quarterly, monthly, or daily.
4
Read the final balance, total contributed, and total interest earned.

Questions

How does compounding frequency change the result?: More frequent compounding applies interest to a smaller period's rate more often, which very slightly increases the final balance compared to less frequent compounding at the same annual rate — daily compounding earns a bit more than annual compounding.
What counts as a 'period' for contributions?: A period matches the compounding frequency you choose — if you pick monthly compounding, the contribution is added once per month, right before that month's interest is applied.
Is this the same as an investment return calculator?: It's closely related — this tool assumes a fixed rate and models the effect of compounding and periodic deposits, which is the core mechanic behind savings accounts, CDs, and simplified investment projections.
Is my financial data sent anywhere?: No. All math runs locally in your browser — nothing is transmitted or stored.