Compound Interest Calculator (With Contributions)

Calculate compound interest with optional regular contributions. Choose yearly, monthly or daily compounding and see how your money grows.

Formula

A = P×(1+r/n)^(n·t) + PMT×((1+r/n)^(n·t) − 1)/(r/n) — P: principal, r: annual rate, n: compounds/year, t: years, PMT: contribution per period

Examples

InputResult
$1,000 at 5% for 10 yrs, monthly$1,647.01
$5,000 at 8% for 5 yrs, yearly$7,346.64
$1,000 at 5% for 10 yrs, $100/month, monthly$17,175.24

Frequently Asked Questions

What is compound interest?

Compound interest is interest earned on both the original principal and on previously accumulated interest, so the balance grows faster over time.

Does compounding frequency matter?

Yes. The more often interest compounds, the higher the final amount for the same nominal rate — monthly compounding beats yearly compounding.

How do contributions change the result?

Each contribution starts earning its own compound interest from the moment it is added, so regular contributions can outgrow a larger one-time deposit over long periods.

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Disclaimer: This calculator is for informational and educational purposes only and does not constitute financial, investment, tax or legal advice. Results are estimates — actual returns, rates and terms vary. Consult a qualified financial professional before making financial decisions.