Buying power over time
Choose a country, enter an amount and two years, and see what the same buying power equals before or after inflation using official annual CPI or HICP data.
How this inflation calculator works
Buying power and CPI
Inflation measures how price levels change over time. If consumer prices rise, the same currency amount buys less. This page uses country CPI / HICP-style annual index data so you can translate an amount between two years and see approximate equivalent buying power, cumulative inflation, and a rough annualised rate.
What the outputs mean
- Equivalent amount — what the starting sum is worth in the other year’s prices using the index path between those years.
- Cumulative inflation — total percent change in the index across the span.
- Annualised inflation — a constant yearly rate that would compound to the same cumulative change.
Worked example
Suppose an index rises from 100 in year A to 130 in year B. Then £100 in year A has about £130 of year-B buying power (or the reverse direction divides). Cumulative inflation is 30%. The annualised figure depends on how many years separate A and B.
Limits of CPI comparisons
Official indexes track a basket of consumer goods and services, not house prices alone, not your personal spending mix, and not every regional market. Basket methodology changes over decades. Use the result as a historical estimate, not a guarantee of what something “should” cost today.
Common mistakes
- Treating wage growth and CPI as the same series.
- Comparing countries without noticing different index definitions.
- Extrapolating one year’s spike as a permanent annual rate.
FAQs
- Which years can I choose?
- Only years covered by the loaded dataset for that country. If a year is missing, pick the nearest available year or another country series.
- Is this compound interest?
- Related maths, but the index path is real published levels — see also Interest for savings-style compounding.
Related: Interest, Salary, Break-Even.
Last updated: July 2026