See what an amount of money from one year is worth in another, using ONS CPI data.
Based on ONS CPI annual averages (series D7BT, 2015 = 100). The latest figure is the August 2026 monthly index, so recent comparisons are approximate.
Prices rarely stand still, so £100 today does not buy what it did twenty years ago. This inflation calculator UK shows what an amount from any year since 1988 is worth in another year, using the ONS consumer prices index as its source, so you can compare old salaries, house prices or savings in today's money.
Quick answer: An inflation calculator UK adjusts money with value = amount × CPI in the later year ÷ CPI in the earlier year, using ONS consumer prices index data. With a CPI annual average of 72.7 in 2000 and an August 2026 index of 143.6, £100 in 2000 is worth about £197.52 today, so prices have almost doubled.
In This Guide
What Is an Inflation Calculator?
An inflation calculator, sometimes called a value of money calculator, adjusts a sum of money for the change in average prices between two dates. It uses a price index, a number that tracks the cost of a typical basket of goods and services. The UK's headline measure is the Consumer Prices Index (CPI), where the 2015 level is set at 100.
The formula is value = amount × CPI in the later year ÷ CPI in the earlier year. The CPI annual average was 72.7 in 2000 and the August 2026 index is 143.6, so £100 in 2000 is worth about £100 × 143.6 ÷ 72.7 = £197.52 today. Prices have almost doubled.
How Do You Use the Inflation Calculator UK?
Step 1: Enter an Amount
You type any sum in pounds, such as an old salary, the price of your first house or a savings balance you want to compare. Type any sum in pounds, such as an old salary, the price of your first house or a savings balance you want to compare.
Step 2: Choose the Years
Pick the year the amount comes from and the year you want to compare it with. Use Swap years to reverse the direction, for example to see what today's money would have been worth in 1995.
Step 3: Check the Index Values
The tool lists the two CPI values it used. Annual averages smooth out monthly swings, while 2026 uses the latest monthly figure, so treat comparisons with the current year as a close estimate rather than an exact figure.
Step 4: Read Your Results
You will see the adjusted value, the total price change, the average yearly inflation rate and the reverse buying power. To find out whether your savings beat inflation, the compound interest calculator lets you compare your account's growth with the average rate shown here over the same period.
What Is £100 From the Past Worth in 2026?
| £100 in | CPI | Worth in 2026 (Aug) |
|---|---|---|
| 1990 | 55.9 | £256.89 |
| 2000 | 72.7 | £197.52 |
| 2010 | 89.4 | £160.63 |
| 2020 | 108.7 | £132.11 |
| 2025 | 138.4 | £103.76 |
Based on CPI to August 2026, £100 in 1990 is worth £256.89, £100 in 2000 is worth £197.52 and £100 in 2020 is worth £132.11. The sharp jump between 2021 and 2023 reflects the energy and food price shock of that period. The Bank of England explains its 2% inflation target and why prices tend to rise gently over time, which is why cash left in a low rate account slowly loses value. Our percentage increase calculator is handy for checking how your own pay rises compare with these figures.
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How we checked this tool: the Tools Veria Editorial Team built this tool by hand, checked it against the official rules or published standards where they apply, and tested it against worked examples. Results are estimates for planning, not personal financial or tax advice. Read our editorial policy and disclaimer, or report an error.
Frequently Asked Questions
How do I calculate the value of money with inflation?
Multiply the amount by the CPI index for the later year and divide by the CPI index for the earlier year. For example, £100 × 143.6 ÷ 72.7 = £197.52.
What is £100 from 2000 worth today?
Using ONS CPI figures, £100 in 2000 is worth about £197.52 in August 2026 money.
Which inflation measure does this calculator use?
It uses the ONS Consumer Prices Index, series D7BT, with 2015 set to 100. Annual averages are used for each full year.
What is the difference between CPI and RPI?
Both measure price changes, but they use different formulas and baskets. RPI usually runs higher than CPI and is no longer a national statistic.
Why is the result different from other inflation calculators?
Some calculators use RPI, monthly figures or a different base year. Small differences are normal and come from the index chosen.
Does inflation affect my savings?
Yes. If your savings earn less interest than the inflation rate, the real buying power of your money falls even though the balance grows.