Return on Investment

Investment Calculator

Most investment calculators assume you will regularly save a fixed regularly every period of time but life isn’t like that.

This calculator estimates the return on investment where irregular savings are made at irregular intervals, accounting for withdrawals too.  The overall calculation is the annualised return on investment.  The assumption made is that money is earning from the day it is invested or the fund reduces immediately you withdraw money.  It is also possible to add dates in the future where the calculator will estimate how much the fund will be if the newly interest rate is applied.

No allowance is made for commission or other costs as the investments are your cash and  the value of the fund is as valued.

Note that the calculator requires Excel macros to be enabled – you will be prompted by Excel when it loads – but if you don’t want to do that you can just insert an annual interest rate in cell C8 and the fund value will be estimated.  The value of delta in cell E8 shows the discrepancy from any target value.


  • Investment dates
  • Investment amounts
  • Current valuation
  • Future dates for valuation

To download this tool, please add your name and email address below