How it works
The annual rate is divided by 12 and returns are added monthly, with contributions at the end of each month. Results are before taxes, fees and inflation. Inside a 401(k) or IRA, growth is tax-deferred or tax-free.
Compound interest calculator
- Methodology & sources
- Runs in your browser
See how your money grows with regular monthly contributions and compound returns.
Future value
$109,333
- Total contributions
- $58,000
- Interest earned
- $51,333
Compounded monthly, contributions at the end of each month, before taxes and fees.
| Contributions | Interest | |
|---|---|---|
| Year 1 | $12,400.00 | $567.39 |
| Year 2 | $14,800.00 | $1,286.60 |
| Year 3 | $17,200.00 | $2,165.39 |
| Year 4 | $19,600.00 | $3,211.93 |
| Year 5 | $22,000.00 | $4,434.80 |
| Year 6 | $24,400.00 | $5,843.03 |
| Year 7 | $26,800.00 | $7,446.09 |
| Year 8 | $29,200.00 | $9,253.96 |
| Year 9 | $31,600.00 | $11,277.11 |
| Year 10 | $34,000.00 | $13,526.55 |
| Year 11 | $36,400.00 | $16,013.87 |
| Year 12 | $38,800.00 | $18,751.23 |
| Year 13 | $41,200.00 | $21,751.44 |
| Year 14 | $43,600.00 | $25,027.92 |
| Year 15 | $46,000.00 | $28,594.83 |
| Year 16 | $48,400.00 | $32,467.01 |
| Year 17 | $50,800.00 | $36,660.09 |
| Year 18 | $53,200.00 | $41,190.49 |
| Year 19 | $55,600.00 | $46,075.46 |
| Year 20 | $58,000.00 | $51,333.14 |
Future value
Frequently asked questions
How does compound interest work?
Your returns are added to your balance and then earn returns themselves, so growth accelerates over time. Time in the market matters more than the exact rate.
What will $10,000 plus $500 a month grow to?
At a 7% annual return compounded monthly, about $691,150 after 30 years: $190,000 contributed and $501,150 of growth.
What is the rule of 72?
Divide 72 by the annual rate to estimate how many years it takes to double your money: about 10 years at 7%, 12 years at 6%.