UK Inflation Impact Calculator

Type an amount, an annual CPI rate, and a number of years — the calculator shows the real-terms value at the end.

Updated May 2026, using HMRC 2026/27 rates and current ONS / gov.uk figures.

Inflation reduces purchasing power over time. £100 today is worth less in real terms in 10 years if prices have risen. ONS publishes monthly CPI; pre-2010 use RPI for historical comparisons.

Worked examples

£10,000 today, 3% CPI for 10 years: real value £7,440

£100,000 cash, 4% CPI for 20 years: real value £45,640 — cash savings can lose half their value.

£50/wk (1990 average grocery) inflated to today: ~£140

Sources: ONS Consumer Price Index · retrieved 2026-05-12.

Frequently asked questions

Why does cash lose value?

Because prices rise. Money in a 0% account is steadily worth less in goods and services. Even savings accounts paying below CPI lose real value.

How does this differ from real return?

Real return is the inverse: subtract inflation from your savings rate. This calculator is the pure inflation effect on a static amount.