Compound Interest Calculator

See how compounding and monthly deposits grow your savings.

Details

Initial investment$

Annual interest rate%Years

Compound frequencyMonthly deposit$Deposit at the start of each month

Future value

$54,713.58

Effective annual yield (APY) 7.229%

Total deposits

$34,000.00

Interest earned

$20,713.58

Rule of 72: doubles in

≈ 10.3 years

Growth over time

BalanceContributions

Year-by-year breakdown

Yearly growth
Year	Total contributed	Total earnings	Balance
1	$12,400.00	$801.42	$13,201.42
2	$14,800.00	$1,834.27	$16,634.27
3	$17,200.00	$3,115.28	$20,315.28
4	$19,600.00	$4,662.39	$24,262.39
5	$22,000.00	$6,494.83	$28,494.83
6	$24,400.00	$8,633.24	$33,033.24
7	$26,800.00	$11,099.74	$37,899.74
8	$29,200.00	$13,918.03	$43,118.03
9	$31,600.00	$17,113.55	$48,713.55
10	$34,000.00	$20,713.58	$54,713.58

About the Compound Interest Calculator

Compound interest is interest earned on interest. This calculator shows how your savings grow with any compounding frequency and regular deposits, and reports the effective annual yield (APY).

How to use it

Enter your starting balance and annual interest rate.
Choose how often interest compounds.
Add a monthly deposit and the number of years.

Formula & method

A = P(1 + r/k)^(k·t) + contributions grown at the same rate
APY = (1 + r/k)^k − 1

Frequently asked questions

How much difference does compounding frequency make?

More frequent compounding earns slightly more. At 5%, yearly compounding gives 5.00% APY while daily compounding gives about 5.13%.

What is the rule of 72?

Divide 72 by the annual rate to estimate how many years it takes money to double. At 6%, money doubles in about 12 years.

Results are estimates for general information only and are not financial, tax, legal or medical advice. Please confirm important decisions with a qualified professional.