Compound Interest Calculator
What regular investing actually grows to, and how much of it charges quietly take. Change the fee box and watch the last figure move.
A projection, not a forecast · no tax or inflation applied
What this shows, and what it does not
Compound growth is the whole argument for investing early, and it is also the easiest thing to overstate. This projects a single steady return so you can see the shape of it: how much of the final pot is money you added, and how much is growth on growth. Real markets do not deliver a steady 7% a year. They deliver something lumpier that averages out over decades, and the order of the good and bad years matters more than most projections admit.
Why the charges box is the one to play with
Change the return and the answer moves a lot, but you do not control the return. You do control charges. Set charges to 0.15% and then to 1.5%, leave everything else alone, and look at what the difference does over 25 years. That gap is the single largest controllable variable in the whole calculation.
Shelter it before you optimise it
Growth outside a tax wrapper is taxable; inside one it is not. An ISA shelters up to £20,000 a year, and a pension adds tax relief at your marginal rate on the way in. Which comes first depends on your rate now against your expected rate in retirement.
Why a single global index fund beats almost everyone covers what to actually hold, and how to actually build wealth in your 30s covers the order to do things in.
General information, not financial advice. Investments can fall as well as rise and past returns are not a guide to future ones.
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