Compound Interest Visualiser
See how compound interest grows any investment over time. Choose frequency and rate. Shows year-by-year breakdown. Free.
How to use
The power of compounding
Albert Einstein allegedly called compound interest "the eighth wonder of the world." At 7% annual return, money doubles roughly every 10 years (the Rule of 72: 72 ÷ rate = years to double). Starting early matters far more than the amount — a 25-year-old investing £100/month will have far more at 65 than a 35-year-old investing £200/month.
Realistic expectations
UK/global stock market historical average: ~7% annually after inflation. High-yield savings accounts: 4–5%. Fixed-rate bonds: 4–5%. Premium Bonds: ~4.4% average prize rate. Index funds over 20+ years have historically beaten most active funds. Past performance does not guarantee future returns.
Einstein supposedly called compound interest 'the eighth wonder of the world' — though there's no evidence he ever actually said this. The maths is real, though: £1,000 at 7% compounded monthly for 30 years becomes £8,116 — eight times your money, with no extra deposits.