Inflation Calculator
Add amounts or use the example values below.
How to Calculate Price Inflation Between Two Prices
Enter the earlier price and later price for the same item or a comparable basket. The calculator measures the change between these two values. For individual items, this is a price-change calculation rather than an official national inflation rate.
- Price difference = later price − earlier price.
- Percentage price change = (later price − earlier price) ÷ earlier price × 100.
- Relative buying power for unchanged cash = earlier price ÷ later price × 100, when the later price is greater than zero.
Worked example: 100 to 112
When a product costs 100 at the earlier date and 112 later, the price difference is 12 and the percentage increase is 12%. The same money has approximately 89.29% of its previous buying power for that product at the higher price.
Price increases, decreases and zero values
A negative percentage means the later price is lower. The earlier price must be greater than zero to calculate a percentage change. Buying-power comparisons are undefined when the later price is zero.
Frequently asked questions
What does this inflation calculator calculate?
It compares two prices supplied by you and reports their percentage change and absolute difference. It does not retrieve consumer-price-index observations.
How do I calculate a 12% price increase?
If the earlier price is 100 and the later price is 112, divide the 12-unit increase by 100 and multiply by 100 to get 12%.
Can a price-change percentage be negative?
Yes. A later price below the earlier price gives a negative percentage, indicating a price decrease.
Does it calculate official inflation for the US or another country?
No. Official CPI inflation uses a representative basket and recorded statistics for a particular country and period.
Can it predict inflation over 10 years?
No. This page currently has only two price fields, not annual inflation rate and years inputs.
What is the difference between inflation and a product price change?
A product price change concerns one selected price; national inflation normally describes a measured price index covering many goods and services.
What does the purchasing-power result mean?
It compares how much of the same item a fixed sum could buy at the two entered prices. It is not a measure of national purchasing power.
Can I use the calculator for salaries or shopping?
Yes, you can compare two amounts, provided they represent a like-for-like comparison. The result is still arithmetic percentage change.
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Interpretation, Limitations and Sources
Inflation rates vary by country, period and product category. This calculator neither predicts future prices nor uses an official historical CPI series. For historical United States consumer price information, consult the U.S. Bureau of Labor Statistics CPI.
For percentage methods, visit the Percentage Calculator. To compare amounts paid and received on a trade, use the Investment Profit Calculator.