Investment fees calculator
A charge of 1% sounds small. Over decades it can cost tens of thousands. Compare two options side by side.
How this is calculated
Each option grows at the growth rate less its total charges, with the starting amount and monthly additions compounded monthly.
The value with no charges shows what was lost to charges in each case, including the growth those charges would have earned.
Fixed-fee platforms charge pounds rather than a percentage. Convert them to a percentage of your pot to compare.
Rates used · 2026/27
| Charges | platform fee plus fund charge |
| Applied | as a reduction in yearly growth |
| Compounding | monthly |
| Growth | your assumption |
Last checked July 2026. Source: HMRC and gov.uk.
Worked example
£50,000 plus £300 a month for 25 years at 6% growth: with 0.3% charges it grows to £405,752, with 1.2% charges to £339,022. The difference is £66,729, from a gap in charges of less than one percentage point.
Common questions
What charges should I add up?
The platform or account fee and the ongoing charge of each fund. Some providers also charge for trades or for switching.
Are lower charges always better?
For the same investment, yes. Higher charges are only worth it if they buy something you value, such as advice.
How do I compare a fixed fee with a percentage fee?
Divide the yearly fixed fee by the value of your pot. A £120 fee on a £40,000 pot is 0.3%.
Do charges matter on a pension?
Very much, because pensions run for decades. The same comparison applies.