Stocks and Shares ISA calculator
See how a Stocks and Shares ISA might grow after platform and fund fees, at three illustrative growth rates. This is an illustration, not a forecast: real returns will differ, and you may get back less than you put in.
The platform changes what you pay, not how your investments perform.
An illustration, not a forecast
Value after fees, before tax. You put in £25,000 over 10 years.
2% a year
£27,199
Fees: £583
5% a year
£31,930
Fees: £697
8% a year
£37,583
Fees: £832
Net growth rate after fees: 1.60%, 4.60%, 7.60%.
How this works
- We show three illustrative annual growth rates before fees (2%, 5% and 8%) side by side. These are round example rates for comparison, not a prediction of what any investment will actually return.
- Fees are modelled as a flat drag on the growth rate: net rate equals the gross rate minus your platform fee minus your fund fee, applied each year. This is a simplification for illustration; a real platform charges fees against your actual balance, which will differ slightly from this method.
- Growth compounds monthly, using the same method as our Cash ISA interest calculator, and your monthly contribution is assumed to be invested at the start of each month.
- "Fees paid" is the difference between what you would have at the gross rate with no fees at all, and what you actually end up with after fees. It illustrates the drag fees have over the term rather than a real fee bill.
- Growth and dividends inside a Stocks and Shares ISA are tax-free, so this calculator does not deduct tax.
- All figures are rounded to the nearest pound.
To compare platforms and their published charges, see our Stocks and Shares ISA comparison.
Tax treatment depends on your circumstances and may change. This is not financial advice.
Questions people ask
Why show three growth rates instead of one?
No one can predict what an investment will return. A lower, a middle and a higher illustrative rate shown side by side make clear how sensitive the outcome is to the return you actually get, which matters more the longer you invest.
Are 2%, 5% and 8% realistic?
They are round, illustrative rates used to show the effect of compounding and fees over time, not a forecast or a promise. Past performance of any investment is not a reliable guide to future returns.
How much difference do fees really make?
More than they look on paper, because they compound too: a fee taken every year shrinks the amount your future growth has to build on. The "fees paid" figure shows this effect over your chosen term at each growth rate.
Do I pay tax on Stocks and Shares ISA growth?
No. Growth and dividends inside a Stocks and Shares ISA are entirely tax-free, whatever your income and however much your investments grow.
What happens to my money if my platform fails?
Your platform is usually covered by the Financial Services Compensation Scheme up to £85,000 per person if it fails. This does not protect you against your investments simply falling in value, which is a separate risk.