Pension erosion calculator
See how inflation reduces the purchasing power of a pension — and how annual increases change the picture.
Pension purchasing power over time
Chart will appear once the inputs are valid.
How to use this calculator
Why fixed pensions lose value
A pension paid as the same number every month buys less each year when prices rise. At 5% inflation a fixed pension keeps only about 61% of its purchasing power after 10 years and about 38% after 20. Annual increases that match inflation protect it; increases below inflation only slow the erosion. You can also check whether your pay has kept pace with the Salary Tracker.
Methodology
The pension in future money is compared with prices that rise at the inflation rate. The ratio is what is left of today’s purchasing power.
Pension 1,500 a month, 5% inflation, 15 years, no increases: 1,500 ÷ 1.0515 ≈ 722 in today’s money — about 48% of today’s purchasing power.
To keep today’s lifestyle it would need to reach about 3,118 a month.
Assumptions
- Inflation and the pension increase are constant every year.
- Amounts are before tax and ignore any other income.
- The “below inflation” case uses half of the inflation rate; the “above inflation” case uses the inflation rate plus 1 percentage point.
- Currency is a label only; no exchange-rate conversion is applied.