Interest Calculator (Simple & Compound)

simple + compound interest
Total interest earned
Final value
Rate used
Total cost

Interest snapshot

Enter the starting amount, annual rate and time period to see both simple and compound interest side by side.

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Simple vs compound interest

  • Simple: Interest = P × r × t, where r is the yearly rate and t is years.
  • Compound: A = P × (1 + r/n)^(nt) — interest earns interest itself, accelerating growth.
  • Rule of 72: divide 72 by the rate to estimate years to double your money.
Estimate only: Estimate only — actual returns depend on the product and compounding frequency.

Frequently asked questions