Inflation Rate Calculator
Compute the inflation rate between two CPI readings, or adjust a dollar amount from one year's prices to another's. Switch methods with the toggle.
One tile of the full inflation unit.
The course teaches inflation interactively — drag the graphs, practice with feedback, and spaced reviews bring it back before you forget. Free.
Enter the price index in each year. The rate is the percent change from the earlier index to the later one.
Inflation rate
+4.00%
Prices rose over the period — this is inflation. Each unit of money now buys less.
What the course adds
Beyond this one page
The inflation unit builds the CPI from a basket of goods, separates demand-pull from cost-push, and weighs the real costs of inflation and deflation — each on interactive graphs, with practice that finds your weak spots.
Spaced reviews
FSRS brings every concept back right before you'd forget. ~50% better retention than re-reading.
Per-concept mastery
Performance Factor Analysis tracks each sub-skill separately — you see which version of the idea is still wobbly.
Diagnostic placement
A short test skips you past what you already know. No re-learning the basics.
The formulas
Inflation rate:
Adjust for inflation:
The CPI is a price index for a fixed basket of goods. A reading of 104 against a base of 100 means the basket costs 4 percent more than in the base year.
Worked example
Suppose the CPI was 100 in 2015 and 130 in 2025. A salary of 50,000 dollars in 2015 — what does it take to match that in 2025?
over the decade
dollars
A 2025 salary of 65,000 dollars buys exactly what 50,000 dollars bought in 2015. Anything less is a pay cut in real terms, even though the number on the paycheck went up.
FAQ
- How do you calculate the inflation rate from CPI?
- The inflation rate is the percent change in the consumer price index between two periods: . If the index rose from 100 to 104, inflation was 4 percent. A negative result means deflation — the average price level fell.
- What is the Consumer Price Index?
- The Consumer Price Index (CPI) tracks the cost of a fixed basket of goods and services that a typical household buys. Statisticians price the same basket period after period, set one year as the base equal to 100, and report every other period relative to it. The percent change in the CPI is the headline measure of inflation.
- How do I adjust a past dollar amount for inflation?
- Multiply the amount by the ratio of the target-year price index to the original-year price index: . This tells you how many dollars in the target year buy what the original amount bought in its own year. It is how economists compare wages or prices across decades.
- What is the difference between nominal and real values?
- A nominal value is measured in the dollars of its own year, with no correction for price changes. A real value is restated in the prices of a single reference year, so amounts from different years can be compared fairly. Adjusting for inflation with the CPI is exactly the step that turns a nominal figure into a real one.
- What does a negative inflation rate mean?
- A negative inflation rate is deflation: the average level of prices fell, so each unit of money buys more than before. Mild deflation might sound good for shoppers, but sustained deflation is dangerous. It encourages people to delay spending while they wait for lower prices, which starves firms of sales and can deepen a recession.
For instructors
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Sends students to the full page with the worked example and related lessons.
Inlines just the interactive widget in your LMS — no nav, no footer, no signup wall.
Ready to go deeper than a calculator?
The Econ Academy macroeconomics course shows where inflation comes from, who it helps and hurts, and how central banks fight it — with interactive graphs and spaced-repetition review.