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The Money CalculatorUK Tax & Finance Tools
Tax year 2026/27  ·  Bank of England base rate 3.75%

Investment growth

See how a lump sum and regular contributions could grow with compound returns. Good for ISAs, pensions or general investing.

Your plan

£
£
%
1 yr20 years45 yr
Projected value
£0
after 20 years

Where it comes from

Returns are assumed steady and compounded monthly — real markets rise and fall. Figures are before inflation, fees and tax. Investments can fall as well as rise.

Common questions

How does compound growth work?

Each year of growth earns growth of its own, so a pot snowballs over time. The calculator applies your expected return to your starting amount and your regular contributions to project the future value.

What return should I assume?

There is no guaranteed figure, but a long-term real return of around 4 to 6% a year is a common, cautious assumption for a diversified stock-market portfolio. Lower assumptions are safer for planning.

Are investment gains taxed?

Inside an ISA, no: growth and withdrawals are tax-free, up to the £20,000 annual allowance. Held outside a tax wrapper, Capital Gains Tax and dividend tax can apply above their annual allowances.

These results are estimates for general information only and are not financial advice. Check every figure yourself and seek appropriate advice from a qualified professional before making any decision. Read the full disclaimer.