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Compound Interest Calculator

Free compound interest calculator. See how your savings or investment grows over time with regular contributions and compounding — useful for building a down payment or growing returns.

Reviewed by the Roomvee editorial teamUpdated June 2026🔒 Runs in your browser — inputs never leave your device
Future balance
$144,572.72
after 20 years
You contributed
$58,000.00
Interest earned
$86,572.72

The power of compound interest

Compound interest means you earn returns on your returns — your money grows faster and faster over time. This calculator combines a one-time deposit with regular monthly contributions, both compounding, to project your future balance.

Why starting early wins

Because growth compounds, the years matter more than the amounts. Money invested in your twenties can outgrow far larger sums invested later, simply because it has more time to compound. Small, consistent contributions add up dramatically over decades.

Frequently asked questions

What is compound interest?

It's interest earned on both your original money and the interest it has already earned, so your balance grows faster and faster over time.

How often should interest compound?

More frequent compounding (monthly or daily) grows money slightly faster than annual compounding, though the difference is small at typical rates.

Why does starting early matter so much?

Because growth compounds over time, the years invested matter more than the amounts. Money invested earlier has far more time to multiply.

Have another question? Get in touch.

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