Compound Interest Calculator

Forecast compound growth for savings or investments with custom contributions and compounding frequency.

Future balance

After 20 years

$222,711.7257.8%

Total interest earned

Growth from compounding

$128,711.72

Represents 57.8% of your ending balance.

Your contributions

Recurring deposits

$84,000.00

Average $4,200.00 per year.

Effective annual yield

With selected compounding

7.23%

Switch to beginning-of-period contributions to squeeze more from the same deposits.

Growth trajectory

Compare how your balance builds from the initial deposit, ongoing contributions, and compound interest.

Starting principal

$10,000.00

Deposits added

$84,000.00

Growth multiple

22.27

Year-by-year breakdown

Track how much of each year's growth came from contributions versus market returns.

Year	Start	Deposits	Interest	End balance
1	$10,000.00	$4,200.00	$860.31	$15,060.31
2	$15,060.31	$4,200.00	$1,226.12	$20,486.42
3	$20,486.42	$4,200.00	$1,618.37	$26,304.79
4	$26,304.79	$4,200.00	$2,038.98	$32,543.77
5	$32,543.77	$4,200.00	$2,490.00	$39,233.77
6	$39,233.77	$4,200.00	$2,973.62	$46,407.39
7	$46,407.39	$4,200.00	$3,492.20	$54,099.58
8	$54,099.58	$4,200.00	$4,048.27	$62,347.85
9	$62,347.85	$4,200.00	$4,644.54	$71,192.39
10	$71,192.39	$4,200.00	$5,283.91	$80,676.30
11	$80,676.30	$4,200.00	$5,969.50	$90,845.80
12	$90,845.80	$4,200.00	$6,704.65	$101,750.45
13	$101,750.45	$4,200.00	$7,492.95	$113,443.41
14	$113,443.41	$4,200.00	$8,338.24	$125,981.64
15	$125,981.64	$4,200.00	$9,244.63	$139,426.27
16	$139,426.27	$4,200.00	$10,216.54	$153,842.81
17	$153,842.81	$4,200.00	$11,258.71	$169,301.53
18	$169,301.53	$4,200.00	$12,376.23	$185,877.75
19	$185,877.75	$4,200.00	$13,574.52	$203,652.28
20	$203,652.28	$4,200.00	$14,859.44	$222,711.72

Milestones to watch

These checkpoints highlight when compounding begins to outpace your own deposits.

Contributions vs. interest
By year 9, interest earned each year exceeds what you add.
Double your starting balance
You cross 2× your initial investment around year 2.
Seven-figure status
Need a bigger contribution or higher return to hit a million within the tracked horizon.
Net gains
Your portfolio outpaces what you put in by $128,711.72.

Compound Interest FAQs