UK inflation calculator
See what an amount from any year since 1948 is worth in today's money, computed from the ONS's own index tables rather than a guess.
Rates taken from the official source and last checked on 14 September 2026.
What the answer means
The calculator compares the ONS's annual average price index for your two years and scales the amount by the ratio. The result is what the same general basket of goods and services would cost, which is the honest version of "what is it worth today": your own basket, heavy on rent or rail fares or whatever it may be, will have moved differently from the average.
It works in both directions. Enter a recent year first and an older year second to deflate: what today's money was worth then.
Worked examples, from the data on this page
£100 in 1995 needs £206 in 2025 to buy the same (CPI). £10 in 1952 needs about £404 (RPI), a reminder that a 4% average compounds brutally over 70 years. Both figures are computed from the index tables this page carries, so they update when the data does.
CPI or RPI, and why we offer both
CPI is the official inflation target measure and the better statistic; it starts in 1988. RPI runs back to 1948, which is why we carry it, and for no other reason: it lost its national statistic status in 2013 because its formula overstates inflation, typically by close to a percentage point a year. For anything since 1988, use CPI. For older money, RPI is the only official route, used with that caveat attached.
One disclosure on method: the RPI index series itself starts at its 1987 rebase. Our figures for 1948 to 1986 are reconstructed by chaining the ONS's own published annual RPI rates backwards from the 1987 index value. Over the years where both exist, the chained figures and the official index agree to within rounding.
Where the data comes from
Three ONS series, linked with check dates on the how we calculate page, refreshed after ONS releases. The base rate page covers the other half of the story: the rate set partly in response to these numbers. And the compound interest calculator answers the forward-looking version of the question, what money grows to rather than what it shrank from.
Common questions
How is the calculation done?
Amount times the price index of the later year divided by the index of the earlier year, using ONS annual averages. £100 at an index of 50 becomes £200 at an index of 100. The average annual rate shown is the geometric mean, which is the compounding-honest way to annualise.
Should I use CPI or RPI?
CPI for anything since 1988: it is the official target measure and the better statistic. RPI exists here because it reaches back to 1948; it overstates inflation by roughly a percentage point a year, which is why it lost national statistic status in 2013.
How much will £1,000 be worth in 10 years?
Genuinely unknowable, and any calculator giving a confident answer is guessing. At the Bank of England's 2% target, £1,000 of today's purchasing power would need about £1,219 in a decade. The last decade ran well above target, which is the argument for treating projections as sketches.
Why does my cost of living feel higher than the official rate?
Because the index is one average basket and nobody buys the average basket. Renters, commuters and parents of small children all run personal inflation rates that can sit well above the headline, while a mortgage-free household in the same year can sit below it. The official number is right about the average and silent about you.