FINANCIAL · COMPOUND INTEREST
Compound Interest Calculator
Calculate how your savings or investment grows with compound interest. See the impact of compounding frequency and regular contributions.
| Category | Amount | Percentage |
|---|---|---|
| Total Contributed | $10,000 | 60.7% |
| Total Interest | $6,470 | 39.3% |
| Period | Balance |
|---|---|
| Yr 1 | $10,512 |
| Yr 2 | $11,049 |
| Yr 3 | $11,615 |
| Yr 4 | $12,209 |
| Yr 5 | $12,834 |
| Yr 6 | $13,490 |
| Yr 7 | $14,180 |
| Yr 8 | $14,906 |
| Yr 9 | $15,668 |
| Yr 10 | $16,470 |
| Year | Contributions | Interest | Balance |
|---|---|---|---|
| 1 | $0.00 | $511.62 | $10,511.62 |
| 2 | $0.00 | $537.79 | $11,049.41 |
| 3 | $0.00 | $565.31 | $11,614.72 |
| 4 | $0.00 | $594.23 | $12,208.95 |
| 5 | $0.00 | $624.64 | $12,833.59 |
| 6 | $0.00 | $656.59 | $13,490.18 |
| 7 | $0.00 | $690.18 | $14,180.36 |
| 8 | $0.00 | $725.49 | $14,905.85 |
| 9 | $0.00 | $762.62 | $15,668.47 |
| 10 | $0.00 | $801.62 | $16,470.09 |
About This Calculator
See how compound interest accelerates the growth of your savings over time. Enter a principal amount, annual return, compounding frequency, optional regular contributions, and time horizon to get a growth projection and year-by-year breakdown.
How It Works
Enter your starting deposit, annual interest rate, and how often interest compounds. Optionally add a regular contribution amount and frequency. The calculator computes your future value using the standard compound interest formula, then generates a year-by-year breakdown and a growth chart so you can see how your balance builds over time.
The Formula
A = P(1 + r/n)^(nt) + C × [(1+r/n)^(nt) − 1] / (r/n)
- A
- future value
- P
- principal (initial deposit)
- r
- annual interest rate (as decimal, e.g. 0.05 for 5%)
- n
- compounding periods per year (12 = monthly, 365 = daily)
- t
- time in years
- C
- contribution per compounding period (annual contribution ÷ n)
Frequently Asked Questions
- What does compounding more frequently do?
- More frequent compounding (daily vs. annually) results in slightly more interest, because each period's interest earns interest sooner. The difference is small at low rates but meaningful over long horizons.
- What is the Rule of 72?
- Divide 72 by your annual interest rate to estimate the number of years it takes to double your money. At 6% it takes about 12 years; at 8% about 9 years. It is an approximation for compound interest only.
- How do regular contributions affect growth?
- Regular contributions can dramatically increase the final balance — often more than the initial deposit alone. This is because each new contribution also earns compound interest for the remaining life of the investment.