Compound interest calculator
Before fees
Platform and fund
Growth is worked out monthly. Real returns go up and down from year to year and are not guaranteed. This does not adjust for inflation.
After 25 years
£112,150
- You paid in
- £61,000
- Growth
- £51,150
How to use it
Put in what you have now, what you can add each month, a yearly return and your yearly fees. The chart shows how much of the final pot is money you paid in and how much is growth.
Try changing just the fees from 0.5% to 1.5%. Over 25 years the gap is usually bigger than people expect, which is why low-cost funds and platforms matter.
Learn more
This is an illustration, not a forecast. When you invest your capital is at risk and you may get back less than you put in.
Questions
Common questions
What is compound interest?
It is interest earned on your interest. Each year your returns are added to your pot, so the next year's growth is worked out on a bigger amount. Over long periods this snowballs.
What return should I use?
For cash savings, use today's savings rate. For a diversified stocks and shares fund, many people test a range like 4% to 7% a year before fees. Returns are not guaranteed and will vary year to year.
Why do fees matter so much?
Fees come off your returns every year, so they compound too. A 1% yearly fee can reduce what you end up with by tens of thousands of pounds over a working life.
Does this include inflation?
No. The results are in future pounds. To get a rough idea in today's money, take your expected inflation rate off the yearly return.
Sources
This tool gives an estimate for general information. It is not tax advice. Check your own position on GOV.UK or with an accountant.