Calculateur d'inflation

À PROPOS DE CET OUTIL

Enter a dollar amount, a start year, an end year, and an inflation rate to see how much purchasing power that amount gained or lost over the period — what a past amount is worth today, or what today's amount will need to grow to just to keep pace years from now. Inflation compounds year over year the same way interest does, so even a modest average rate erodes purchasing power significantly across a decade or two. Results depend entirely on the rate you supply, so historical CPI-based averages give a defensible read on the past, while a rate you assume yourself is really a projection, and the two produce very different pictures depending on which one you're using.

COMMENT UTILISER

1. Enter the dollar amount you want to adjust.
2. Enter the starting year for that amount.
3. Enter the ending year you want to compare against.
4. Enter an inflation rate — a historical average or your own assumption.
5. Read the adjusted value and the total percentage change in purchasing power.

CAS D'USAGE COURANTS

• Comparing a decades-old salary or price to today's dollars to judge whether a historical figure was actually generous.
• Estimating how much a fixed pension or savings goal needs to grow just to maintain today's buying power in 20 years.
• Adjusting old family records, like a home purchase price or tuition bill, to a modern equivalent for context.
• Stress-testing a retirement plan by seeing how sustained inflation erodes a fixed nest egg over a long retirement.
• Explaining to students why a dollar today isn't worth the same as a dollar decades from now, with concrete numbers.

CONSEILS ET ERREURS COURANTES

• Inflation compounds rather than adding up linearly, so doubling the number of years more than doubles the cumulative effect.
• Real historical inflation varies widely year to year; a single average smooths that out and hides periods of high or low inflation.
• Wages and prices don't always move together, so an inflation-adjusted salary figure doesn't guarantee an equivalent real raise occurred.
• For future projections, small changes in the assumed rate produce large differences in outcome over 20-to-30-year horizons.

AUTRES QUESTIONS

What inflation rate should I use if I don't know the historical figure for a specific period?

Look up the actual historical rate or average CPI change for those years if precision matters. Otherwise, use a general long-run rate as a rough placeholder, treating the result as an estimate rather than an exact historical figure.

Is this the same as the Consumer Price Index (CPI)?

CPI is one common government measure that inflation rates are often derived from, but this tool doesn't fetch live CPI data — it simply applies whatever rate you enter to the calculation.

Can I use this to project forward instead of adjusting a past amount?

Yes. Set the end year in the future and enter an assumed future inflation rate to see what today's amount would need to grow to in order to maintain the same purchasing power.

Does inflation affect every category of spending equally?

No. Categories like housing, healthcare, and food often inflate at different rates than the broader average. This tool applies one uniform rate, so results are a general approximation rather than a category-specific breakdown.

GUIDES ASSOCIÉS

OUTILS ASSOCIÉS