UK Inflation Calculator: What Is £X From a Past Year Worth Today?
For example: £100 in January 2015 has the same buying power as roughly £144 in July 2026, based on official CPI figures.
Use the calculator below to compare any amount of money between any two months from January 1988 to today. It's powered directly by the Consumer Prices Index (CPI), the UK's official measure of inflation.
How this calculator works
The calculator takes the CPI index value for your "from" month and your "to" month, then scales your amount by the ratio between them: amount × (index at "to" ÷ index at "from"). This is the standard method used across government and academic inflation calculators — it directly reflects how much the overall price level has moved between the two dates, rather than relying on year-by-year compounding of rounded annual rates.
CPI vs CPIH vs RPI — what's the difference?
The UK publishes three overlapping measures of inflation, and it's easy to see different-looking numbers in the news without knowing why:
- CPI (Consumer Prices Index) — the headline measure used on this page, and the one the Bank of England's 2% inflation target is defined in. It doesn't include owner-occupier housing costs.
- CPIH — CPI plus an estimate of the costs of owning and living in your own home (based on rental equivalence). ONS treats this as its lead statistical measure, though CPI remains more widely quoted.
- RPI (Retail Prices Index) — an older measure that has been stripped of its "National Statistic" status due to known methodological issues, but is still used in some long-standing contracts (like index-linked gilts and some rail fares). RPI tends to run higher than CPI.
Why does inflation feel different to me than the official rate?
CPI is a weighted average across thousands of goods and services bought by a "typical" UK household. If your own spending leans heavily on categories that have risen faster than average — energy and food are common examples during periods of high inflation — your personal experience of price rises can run noticeably above the headline figure, even though the calculation itself is accurate. The opposite is also true: if you spend little on the categories driving inflation, prices may feel more stable to you than the headline number suggests.
Frequently asked questions
What counts as the 'base year' for this calculator?
The underlying CPI series is indexed so that 2015 = 100 — every other month's index value is relative to that anchor point. It's just a reference for the index numbers themselves; it doesn't limit which years you can compare, and the calculator handles the arithmetic either way.
Does this include housing costs like rent or mortgages?
CPI (the measure used here) does not include owner-occupier housing costs such as mortgage interest. A separate measure, CPIH, does include an estimate for housing costs. CPI is used here because it's the measure most commonly quoted in the news and the one the Bank of England's 2% target is defined in terms of.
How far back does the data go?
The official CPI series used on this page runs from January 1988 to July 2026, refreshed automatically each month.
Where does the data come from?
Directly from the Office for National Statistics' published CPI time series dataset (the 'MM23' release), specifically the CPI INDEX 00: ALL ITEMS series. No third-party or estimated figures are used.
Data source: ONS Consumer Price Inflation time series (MM23). Latest available month: July 2026. Figures on this page were last refreshed 13 September 2026.