Compound Interest Calculator

See how your money grows over time with the power of compounding

Your Investment
Adjust the values to see how your money grows
$10,000
$100
5%
10 years

Future Value

$31,998.32

After 10 years at 5% APR (5.12% APY)

Total Contributions

$22,000.00

Interest Earned

$9,998.32

💡

APR vs APY

Your 5% APR with monthly compounding equals 5.12% APY. Convert APY ↔ APR →

Year-by-Year Growth
See how your investment grows each year
YearBalanceContributionsInterest
1$11,739.50$11,200.00$539.50
2$13,568.01$12,400.00$1,168.01
3$15,490.06$13,600.00$1,890.06
4$17,510.44$14,800.00$2,710.44
5$19,634.20$16,000.00$3,634.20
6$21,866.60$17,200.00$4,666.60
7$24,213.23$18,400.00$5,813.23
8$26,679.91$19,600.00$7,079.91
9$29,272.79$20,800.00$8,472.79
10$31,998.32$22,000.00$9,998.32

How Compound Interest Works

The Magic of Compounding

Compound interest is often called the "eighth wonder of the world" because of its powerful ability to grow wealth over time. Unlike simple interest, which only earns on the principal, compound interest earns interest on your interest.

The more frequently interest compounds, the faster your money grows. This is why APY (Annual Percentage Yield) is always higher than APR (Annual Percentage Rate) when compounding occurs more than once per year.

The Compound Interest Formula

A = P(1 + r/n)nt

  • A = Final amount
  • P = Principal (initial investment)
  • r = Annual interest rate (decimal)
  • n = Number of times compounded per year
  • t = Time in years
The Rule of 72

A quick way to estimate how long it takes to double your money: divide 72 by your interest rate.

At 5%, your money doubles in approximately 14.4 years

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