Inflation loss calculator
Use this calculator to estimate how inflation reduces purchasing power over time. Enter an amount and choose a start year and end year to see the inflation-adjusted equivalent amount, inflation shortfall, shortfall percentage, and the cumulative inflation factor. Because inflation compounds, longer ranges can change the result materially.
Example (based on United States CPI): $1,000 in 2000 is equivalent to approximately $1,801 in 2025.
- Equivalent amount = A × (CPIend/CPIstart)
- Inflation factor = CPIend/CPIstart
- No external CPI APIs
See Methodology and Sources.
Inflation loss calculator
See how inflation changes purchasing power over time. Compare two years using CPI ratios to estimate the inflation-adjusted equivalent amount, the inflation shortfall, and the cumulative inflation factor.
Each point shows the CPI-adjusted value in 2000 prices. Lower values indicate less purchasing power.
CPI values vary by source and methodology. This site uses locally stored CPI series and the formula in docs/DATA_MODEL.md.
Country context
Data coverage and source details for the CPI series used on this page.
How to interpret the results
The calculator keeps values in the same currency and adjusts only for changes in the price level, using CPI. If the inflation-adjusted equivalent is higher than the nominal amount, the difference is the inflation shortfall—how much more you’d need in the end year to match the start-year purchasing power.
The cumulative inflation factor shows how much the CPI index changed over the period. For example, an inflation factor of 1.50× means the CPI index increased by 50% from the start year to the end year, which (roughly) corresponds to prices being about 50% higher on average.
How the math works
The calculator uses CPI index ratios, as described in docs/DATA_MODEL.md:
- Equivalent amount = A × (CPIend / CPIstart)
- Inflation shortfall = equivalent amount − A
- Shortfall percent = (inflation shortfall / equivalent amount) × 100
- Inflation factor = CPIend / CPIstart
Country pages and data coverage
For country-specific context (currency, CPI coverage, sources, and related preset pages), pick a country below. These pages are statically generated from /data/config.ts presets and CPI JSON files in /data/cpi.
FAQ
Answers to common questions about CPI-based inflation loss estimates.
What does the calculator output mean?
The equivalent amount estimates what your start-year amount is worth in end-year prices. Inflation shortfall is the additional amount you’d need in the end year to match the start-year purchasing power (same currency).
What is the “cumulative inflation factor”?
It’s the CPI_end / CPI_start ratio. A factor of 2.0 means prices roughly doubled over the period (on the CPI index used).
Is this the same as exchange rates?
No. This calculator stays in the same currency and uses CPI ratios to adjust for changes in the domestic price level. It does not convert between currencies.
Why do results differ from other sites?
Different sources use different CPI series, rebasing, seasonal adjustments, and rounding. This site uses the CPI values stored in /data/cpi for each country.