UK Inflation Calculator

How UK Inflation Affects Your Money

Inflation measures how quickly prices rise over time. When inflation is positive, your money buys less each year — a pound today is worth more than a pound tomorrow. The UK uses the Consumer Prices Index (CPI) to track this. Our calculator converts amounts between any two years from 2000 to 2026, so you can see what historical sums would be worth today, or project future purchasing power.

Understanding the CPI Index

The Office for National Statistics (ONS) publishes the CPI with 2015 as the base year (index = 100). A value of 122 means prices are 22% higher than in 2015. By comparing the index in two years, we can convert money between them: the adjusted amount = original × (end CPI ÷ start CPI). That's exactly what our calculator does.

Inflation and Savings

When savings rates sit below inflation — as they often did in the 2010s and early 2020s — your money loses real value even if the number in your account grows. Earning 2% on £10,000 gives you £10,200, but if inflation is 3%, you'd need £10,300 to match the original purchasing power. Use our savings calculator with the inflation toggle to see real returns, or this inflation calculator to understand how prices have moved over time.

Past vs Future

In Past → Present mode, you enter an amount from a past year and see its value in the end year (typically today). "What was £1,000 in 2010 worth in 2024?" In Present → Future mode, you enter an amount in the start year and project it forward — useful for planning how much you'll need to maintain purchasing power. The formula works both ways; only the direction of the label changes.

Frequently Asked Questions

What is the UK CPI index?

The Consumer Prices Index (CPI) measures the average change in prices of a basket of goods and services. The ONS sets a base year (2015 = 100) and tracks how prices move. A higher index means higher prices and lower purchasing power. Our calculator uses approximate UK CPI values from 2000 to 2026.

How does inflation erode savings?

If inflation exceeds your savings rate, your money loses purchasing power. For example, with inflation at 3%, you need a return of at least 3% to stay level in real terms. Use our inflation calculator to see how much prices have risen over your chosen period, and compare with savings or investment returns.

How do I convert historical amounts to today's money?

Use the formula: adjusted value = amount × (CPI in end year ÷ CPI in start year). Our calculator does this automatically. Select Past → Present, enter the amount and the year it's from, then choose the end year (e.g. 2026). You'll see what that sum would buy in today's prices.

Why do the CPI values in the calculator differ from ONS?

Our calculator uses approximate UK CPI values for illustration. The Office for National Statistics publishes the official figures; we provide a simplified dataset for quick comparisons. For precise historical analysis, refer to the ONS inflation data.