A salary of $30,000 sounds very different depending on the year attached to it. In 1990 it was a solid income; today it is below the median. The money did not change, but what it buys did. Converting an amount from one year into another is how you compare across time honestly, and the tool that does it is a price index.
TL;DR — Enter an amount, a start year and an end year in the CPI inflation calculator to see the equivalent value, the total inflation between the years and the average rate per year.
How the conversion works
The US Consumer Price Index (CPI-U) measures the cost of a typical basket of goods and services, set to 100 for the 1982 to 1984 period. Every year has an index value: 1990 sits at about 130.7, and 2024 at about 313.7. To convert money between two years, you multiply by the ratio of their index values.
So $100 in 1990, expressed in 2024 money, is:
$100 × (313.7 ÷ 130.7) ≈ $240
That single ratio is the whole method. Flip the years and you convert the other way. The calculator carries the full annual-average table back to 1913, so any pair of years works.
Reading the three numbers
The tool returns more than one figure, and each answers a different question.
- Equivalent value is the headline: what the amount is worth in the other year’s money. It is the fairest way to compare a wage, a price or a savings balance across time.
- Cumulative inflation is the total price change across the whole span, as a percent. From 1990 to 2024 that is about 140%, meaning prices more than doubled.
- Average per year spreads that change across each year. The same 1990 to 2024 span works out to roughly 2.6% a year, which is why the headline total looks so large over decades.
The gap between the cumulative and the yearly figure is the point most people miss. A modest 2.6% a year feels harmless, yet compounded across a working life it more than doubles prices.
Where CPI and your own costs part ways
CPI is an average across the whole country and a fixed basket. Your own inflation rate depends on where you live and what you spend on. Rent in a growing city, health insurance and college tuition have all outrun the headline index for years, while electronics and some clothing have fallen. If a number from the calculator feels low against your own experience, this is usually why.
Use it for what it is good at: comparing salaries across decades, checking whether a raise kept pace with prices, or putting a historical figure into terms you can feel. For a forward-looking view of how future inflation might erode a fixed sum, the inflation calculator projects a rate over a set number of years instead.
