Compound Interest Calculator
See how savings grow with compound interest — choose the compounding frequency and add monthly contributions.
Runs in your browser — nothing is uploadedEnter values
Compounded
Result
- Total interest
- $10,096.61
- Total paid in
- $10,000.00
- Effective annual rate
- 7.229%
How it's calculated
A = P × (1 + r ÷ n)^(n × t)
= $10,000.00 × (1 + 7% ÷ 12)^(12 × 10)
Year-by-year growth
| Year | Total paid in | Interest earned | Balance |
|---|---|---|---|
| Year 1 | $10,000.00 | $722.90 | $10,722.90 |
| Year 2 | $10,000.00 | $1,498.06 | $11,498.06 |
| Year 3 | $10,000.00 | $2,329.26 | $12,329.26 |
| Year 4 | $10,000.00 | $3,220.54 | $13,220.54 |
| Year 5 | $10,000.00 | $4,176.25 | $14,176.25 |
| Year 6 | $10,000.00 | $5,201.06 | $15,201.06 |
| Year 7 | $10,000.00 | $6,299.94 | $16,299.94 |
| Year 8 | $10,000.00 | $7,478.26 | $17,478.26 |
| Year 9 | $10,000.00 | $8,741.77 | $18,741.77 |
| Year 10 | $10,000.00 | $10,096.61 | $20,096.61 |
About Compound Interest Calculator
Compound interest earns interest on both your original amount and the interest already added. Over time this snowball effect makes savings grow much faster than simple interest — and makes debt more expensive.
Choose how often interest compounds (yearly, quarterly, monthly or daily), add optional monthly contributions and see the final balance, total contributions and total interest earned.
When to use it
- Planning savings for education, a house deposit or retirement.
- Comparing savings accounts or deposits with different compounding.
- Showing the long-term effect of saving a fixed amount every month.
- Understanding how debt grows when interest is not paid.
Tips for better results
- Starting early matters more than the amount — time drives compounding.
- More frequent compounding gives a slightly higher return at the same rate.
- Use the effective annual rate to compare accounts with different compounding periods.
How to use the Compound Interest Calculator
- Enter the starting amount, rate and years.
- Choose how often interest compounds.
- Optionally add a monthly contribution.
Frequently asked questions
What is compound interest?
Interest that is added to your balance and then earns interest itself. Over time this "interest on interest" makes balances grow faster.
What is the effective annual rate?
The yearly rate after compounding. 7% compounded monthly is an effective 7.23% per year.
What is the Rule of 72?
Divide 72 by the yearly interest rate to estimate how many years it takes for money to double. At 8%, money roughly doubles in 9 years.
Does the calculator include tax or inflation?
No. It shows the nominal growth. Taxes on interest and inflation reduce the real value of your savings, so consider them in your planning.