Compound growth calculator
Illustrate monthly compounding with an initial amount, monthly contributions, an assumed annual rate, and whole years.
Try a worked example
Try a worked example
Illustrate monthly compounding with an initial amount, monthly contributions, an assumed annual rate, and whole years.
Check the units and options, then use the tool’s calculation button. The example is fictitious; replace its values for your own calculation.
Illustration only. Supply the applicable rates and assumptions yourself; this is not financial, tax or legal advice.
Example input
- Starting amount
- 10000
- Monthly contribution
- 200
- Annual rate (%; divided by 12 monthly)
- 4
- Number of whole years
- 10
- Currency
- EUR €
Expected output
Illustrative ending balance: €44,358.29 Total contributions: €34,000.00 Illustrative growth: €10,358.29 Assumes a constant rate, monthly compounding, and end-of-month contributions. Excludes tax, inflation, and fees.
Shows an illustrative balance with monthly interest applied before each end-of-month contribution.
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Method and limits
The result depends on the values entered and the method shown. Check the assumptions, rates, or rules that apply to your situation before using it. Illustrative result only. Verify the rules and assumptions that apply to your work.
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Quick answer
Shows an illustrative balance with monthly interest applied before each end-of-month contribution.
The page code is downloaded when you open it; values are handled in your browser.
Limits of the result
The result depends on the values entered and the method shown. Check the assumptions, rates, or rules that apply to your situation before using it. Illustrative result only. Verify the rules and assumptions that apply to your work.
Frequently asked questions
What does the calculation include?
Each month, the balance is multiplied by 1 + annual rate ÷ 12, then the monthly contribution is added at month end. The total contributions equal the starting amount plus monthly contribution × 12 × whole years; illustrative growth is ending balance minus total contributions. For example, 10,000 at 4% earns 33.33 in first-month interest before a 200 contribution is added. This assumes a constant non-negative rate, whole years from 1 to 80, and no fees, tax, or inflation; it is a scenario, not a forecast or recommendation.
Which values should I enter?
Illustrate monthly compounding with an initial amount, monthly contributions, an assumed annual rate, and whole years. Use consistent amounts, units, and time periods.
Is the result definitive?
No. Check the assumptions and rules that apply to your situation; this is an illustrative calculation, not professional advice.
Sources and references
These references describe the cited context and rules; some apply only in the jurisdiction named in their title. They do not validate this illustrative calculation.