Inflation Calculator

Compare buying power between two years using CPI-based reference data. See adjusted value, total inflation, annualized rate, and step-by-step work.

How to Use

  1. Enter an original dollar amount.
  2. Select the starting year and target year.
  3. Choose the calculation direction if needed.
  4. Review the adjusted value, inflation change, annualized rate, and Show Work.
Buying Power View
Fast CPI-based comparison for money across time.
Adjusted Value
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Change
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Annualized
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Years
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Original Amount Adjusted Amount
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$—
Status: Waiting for input
Data Basis: Built-in CPI dataset
Start CPI
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End CPI
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Difference
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Multiplier
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Inputs & Settings
Enter an amount and two years. The tool calculates equivalent purchasing power using the built-in CPI dataset.
Enter the original dollar amount to compare.
Display formatting only. Calculation remains deterministic.
Starting year for the original buying power.
Target year for the adjusted value.
Show Work (step-by-step)
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Work should show the CPI ratio, multiplier used, adjusted amount, total percentage change, and annualized inflation formula.

Inflation Formula

Quick answer: An inflation-adjusted amount is typically calculated as Adjusted Amount = Original Amount × (Target CPI ÷ Start CPI).

This tool uses built-in CPI reference values loaded in JavaScript so the calculator works fully in the browser.

  • Adjusted amount: Amount × (CPItarget ÷ CPIstart)
  • Total inflation: ((Adjusted − Original) ÷ Original) × 100
  • Annualized inflation: ((CPItarget ÷ CPIstart)1 ÷ years − 1) × 100
Reference: CPI values displayed by the tool should match the built-in dataset used by the JavaScript file.

FAQ

What does this inflation calculator do?

It compares the buying power of a dollar amount between two years using CPI-based reference values.

Does it predict future inflation?

No. This tool is for deterministic comparison using built-in reference data, not forecasting.

Why can the annualized rate differ from the total percentage change?

Total inflation is cumulative across the full period, while the annualized rate expresses the equivalent average yearly change.

Can I compare newer and older years in either direction?

Yes. The tool can compare older to newer years or reverse the comparison depending on the selected mode.

Tool Info

Last updated:

Updates may include UI improvements, accessibility refinements, and CPI dataset handling improvements in the tool JavaScript.