How compound interest works
Interest is added to your balance, then future interest is earned on both your deposits and past interest.
TIME × RATE × CONSISTENCY
Compound Interest Calculator
Calculate how your money grows through compound interest and regular contributions.
YOUR INPUTS
Advanced options
PROJECTED VALUE120 months
$94,111.23
Final balance$94,111.23
Total contributions$70,000.00
Growth / interest$24,111.23
Inflation-adjusted$73,519.55
BALANCE OVER TIME$94,111
YEAR-BY-YEAR
| Period | Final balance | Total contributions | Growth / interest |
|---|---|---|---|
| 12 months | $16,651.05 | $16,000.00 | $651.05 |
| 24 months | $23,642.37 | $22,000.00 | $1,642.37 |
| 36 months | $30,991.39 | $28,000.00 | $2,991.39 |
| 48 months | $38,716.40 | $34,000.00 | $4,716.40 |
| 60 months | $46,836.63 | $40,000.00 | $6,836.63 |
| 72 months | $55,372.31 | $46,000.00 | $9,372.31 |
| 84 months | $64,344.69 | $52,000.00 | $12,344.69 |
| 96 months | $73,776.11 | $58,000.00 | $15,776.11 |
| 108 months | $83,690.06 | $64,000.00 | $19,690.06 |
| 120 months | $94,111.23 | $70,000.00 | $24,111.23 |
Why time matters
Compounding is nonlinear. The later years often create more growth than the early years, even when the rate stays unchanged.
Contribution timing
Beginning-of-period contributions receive one extra period of growth compared with end-of-period contributions.
How the Compound Interest Calculator works
Calculations run entirely in your browser. We apply the formulas shown above to a month-by-month schedule, hold your entered rate constant, and treat every result as an estimate—not a forecast or bank quote.
FREQUENTLY ASKED QUESTIONS
Clear answers. Better inputs.
What is compound interest?+
It is interest earned on both the original principal and previously credited interest.
Is daily compounding better?+
At the same nominal rate, more frequent compounding produces slightly more growth. At the same APY, annual growth is already equivalent.
What return should I enter?+
Use a rate appropriate to the product or a range of scenarios. A calculator is not a return forecast.