Investment Yield (Growth Rate) Calculator - how well have your savings or investments performed?
Click here to launch the calculator
This calculator works out the annualised growth rate of an investment over a number of years based upon the original investment.
It can calculate the growth rate of single-premium investment (such as an investment bond) or a regular premium investment (such as a personal pension).
Please note that the calculator assumes that no withdrawals have been taken from the investment during the period in question.
While calculating a yield or growth rate for a single-premium investment is relatively straightforward, calculating an average growth rate based on a regular monthly contribution is more difficult. In effect it is more of a very close approximation.
For instance, if you were to pay £50 per month into a savings plan for ten years and at year ten it was worth £10,000, in order to calculate the true growth rate exactly, you would need to calculate the number of units purchased each month, then track the growth of those specific units for the remainder of the term. This would effectively entail a polynomial order of 120 separate calculations to solve.
Also you would need accurate details of each payment, and assuming you actually had all the information, it would still be a time-consuming task. Therefore, if this is not possible, the alternative method is to use an iterative approach, incorporating the Newton-Raphson root-finding method (similar to methods used in Excel functions such as RATE). This is the method used by this calculator.
The figures projected by the calculator are only for guidance purposes, and are by no means guaranteed.
Recent Financial Topics
The deal includes travel, mobile phone and AA breakdown cover.
Chase current account customers can now get insurance in their banking app: Is it a good deal?
03/02/2026 07:01 PM
The property portal analysed millions of homes listed for sale over a ten-year period to find the month that houses were most likely to sell.
THIS is the best month to put your house up for sale, Rightmove says - and it's not in the spring
03/02/2026 07:01 PM
I recently moved into a new house. The process was a bit acrimonious, as the initial buyer pulled out and the sellers of my new property were annoyed.
Sellers ripped carpets and appliances out of my new home. Should I take legal action? DEAN DUNHAM replies
03/02/2026 05:10 PM