Finance

Calculateur d’Inflation

Ajustez un montant entre deux années via l’IPC, ou projetez la valeur future à un taux d’inflation.

Calculer

€

Used in future-value mode.

%

Used in future-value mode.

Updates as you type

Résultat

—

La formule

Historical mode: Amount_to = Amount_from × (CPI_to ÷ CPI_from) using annual-average CPI-U (1982–84=100). Forward mode: Future = Present × (1 + rate)^years — the same compound-growth math used for inflation projections.

Adjusted = Amount × CPI₂/CPI₁ · FV = PV × (1+r)^n

Exemple détaillé

  1. $10,000 in 1990 → CPI≈130.7; in 2024 CPI≈313.7
  2. Factor ≈ 313.7/130.7 ≈ 2.40
  3. ≈ $24,000 in 2024 purchasing-power terms

Résultat: $10k (1990) ≈ $24k (2024) CPI-adjusted

How inflation adjustment works

Price indexes turn “how many dollars” into “how much buying power.”

CPI-U series

We use approximate annual-average Consumer Price Index for All Urban Consumers (CPI-U), indexed to 1982–84=100, in the spirit of BLS publications. Values are rounded teaching approximations — not a substitute for downloading official BLS tables for legal or contractual use.

Forward projection

Compounding at a constant annual rate illustrates purchasing-power loss (or the nominal dollars needed to keep pace). Real returns require subtracting inflation from investment yields separately.

Limits

CPI baskets change; local inflation differs from the U.S. average; housing and healthcare components can diverge. Use country-specific indexes when precision matters outside the U.S.

Faits intéressants

Rule of 72

At ~3%/year inflation, prices roughly double in 72÷3 ≈ 24 years — a quick mental check.

Nominal vs real

A 5% raise with 3% inflation is about 2% real. Always compare rates on the same basis.

CPI vs PCE

The Fed often cites PCE; consumers know CPI better. Levels differ slightly; both track inflation.

Deflation years

If the later CPI is lower, adjusted amounts shrink — money gained purchasing power.

Not an investment return

This adjusts for prices — it does not model stock or bond returns.

Questions fréquentes

Choose Historical, enter the amount and both years. We multiply by the ratio of annual CPI-U values.

Set year-from to 1990 and year-to to a recent year (e.g. 2024). The result applies the CPI ratio to $10,000.

Enter today’s amount, an annual inflation rate, and years. FV = amount × (1+rate)^years.

It is an approximate CPI-U teaching series aligned with BLS methodology. Download official series from BLS for contractual or research precision.

Références

  1. Consumer Price Index (CPI) — U.S. Bureau of Labor Statistics Official CPI overview and data access.
  2. CPI inflation calculator — U.S. Bureau of Labor Statistics BLS’s own dollar-conversion tool.
  3. Inflation concepts — Federal Reserve Education Educational materials on inflation and purchasing power.