Investment calculator

The investment calculator simulates the growth of a one-off lump sum and/or regular monthly contributions. Check how time and expected return affect the result and get a feel for the power of compound interest. The result is informational. Numbers use European format (e.g. 1.000 for one thousand, 7,00 for seven).

Investment result

Final value
Total contributed
Profit
? Tip: click 'Save for comparison', then change the inputs and recalculate. The chart will show the saved (grey) and current (green) curves side-by-side.

Notes and limitations

How the calculation works

  • Total contributed is the sum of the initial contribution and all monthly contributions (without return).
  • Final value includes the compound effect at a constant monthly return (annual return / 12).
  • Assumption: monthly contributions are paid at the end of the month, so over short periods (e.g. 1 year) some contributions earn for less time.
  • Profit = final value − total contributed.
  • Difference (run 2 − run 1) compares the current calculation with the saved one. A negative profit difference means the second run had higher contributions but the final value didn't grow proportionally.

This calculator is an informational estimate. Returns are not guaranteed and can vary widely from year to year.