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Inflation Calculator
See how inflation eats into the value of money over time. Find what an amount will buy in future, in today's money, and how much you'd need to keep the same spending power.
A steady-rate projection, not real historical inflation. An estimate to show the effect, not financial advice.
How the spending power of £10,000 falls over time at 2.5% inflation, measured in today's money.
How inflation eats into money
Inflation means prices creep up, so a fixed pile of cash buys less as the years pass. The calculator shows this two ways: what your money will actually buy in the future, measured in today's spending power, and how much you would need in future to buy the same things you can today. The longer the timeframe and the higher the rate, the bigger the gap.
It is why money sitting idle loses value in real terms, and why savings and investments aim to at least keep pace with inflation.
Common questions
What is inflation?
Inflation is the rate at which prices rise over time. When prices go up, each pound buys a little less, so the same amount of money has less spending power in the future. A 2.5% inflation rate means something costing £100 today would cost £102.50 in a year.
How does inflation affect my savings?
If your savings earn less interest than the inflation rate, their spending power falls over time even though the balance looks the same or larger. To protect your money you generally need a return at least equal to inflation. This is why cash left idle slowly loses value.
What inflation rate should I use?
The Bank of England targets 2% a year, so 2% to 3% is a reasonable long-run assumption. Inflation can spike well above that for periods, as it did recently, so it is worth trying a higher rate to see the effect on longer timeframes.
What is the difference between the two figures?
One shows what your money will buy in the future, in today's spending power, so it goes down. The other shows how much you would need in future pounds to buy what your money buys today, so it goes up. They are two sides of the same coin.
Does this use real historical inflation?
No. It uses a steady rate that you choose, so it is a projection rather than a record of past prices. Real inflation varies year to year, so treat the result as a guide to the effect, not an exact figure.
About this calculator
Uses a steady inflation rate that you set and standard compounding, so it is a projection of the effect rather than a record of real past prices, which vary year to year. An estimate to help you plan, not financial advice. Last updated June 2026.