📈 InvestmentCompound Interest Calculator

Compound Interest Calculator

Watch your money grow over time with compound interest and regular contributions.

UPDATED · MAY 2026
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After 20 years at 8.00%
$49,268
CONTRIBUTED$10,000
INTEREST$39,268
Future value
$49,268
Total invested
$10,000
Interest earned
$39,268
GROWTH OVER TIME
Total value Invested
$0$13K$25K$38K$50K0y5y10y15y20y
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How to use the Compound Interest Calculator

  1. 01
    Enter your starting amount. Your initial deposit or balance.
  2. 02
    Add monthly contributions. Optional regular deposits that compound too.
  3. 03
    Set rate, years, and frequency. Watch the future value and the growth chart update.

How is it calculated?

Compound interest earns returns on both your principal and previously earned interest. Each period the balance is multiplied by (1 + rate/frequency) and your contribution is added. More frequent compounding and longer time horizons dramatically increase the final value — this is the snowball effect that makes time your biggest ally.

Frequently asked

The questions readers ask most about the compound interest calculator.

More frequent compounding (monthly vs annually) earns slightly more because interest starts earning interest sooner. The effect grows with rate and time.
LEARNCompound interest explained: how money grows over time