Calculators

Compound Interest Calculator

See how your savings or investments grow over time with compound interest. Enter principal, interest rate, time, and compounding frequency.

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Final Amount
$20,096.61
Interest Earned
$10,096.61

Usage notes

  • The Rule of 72: divide 72 by the annual rate to estimate how many years it takes to double your money.
  • More frequent compounding (daily vs. annually) yields slightly more interest.
  • This calculator does not include additional regular contributions — it calculates growth of a single lump sum.

How to Use This Tool

  1. 1Enter your initial investment (principal).
  2. 2Set the annual interest rate as a percentage.
  3. 3Enter the number of years.
  4. 4Choose how often interest compounds (monthly, quarterly, etc.).
  5. 5The calculator shows the final amount and total interest earned.

Frequently Asked Questions

What is compound interest?
Interest calculated on both the initial principal and the accumulated interest from previous periods. It makes your money grow faster than simple interest.
What is the Rule of 72?
A quick estimation: divide 72 by your annual interest rate to get the approximate number of years to double your investment. At 8%, it takes about 9 years.
Does compounding frequency matter much?
Yes, but the difference shrinks at higher frequencies. Monthly vs. annually can make a noticeable difference; daily vs. monthly is minimal.
Does this include regular deposits?
No. This calculates growth of a single initial investment. For regular contribution calculations, a more advanced savings calculator would be needed.