Inflation Calculator
Calculate how prices grow with inflation and how much purchasing power money loses over time, using an annual rate or two CPI index values.
Results
- Assumes a constant inflation rate compounded yearly: future cost = amount × (1 + rate)^years. With CPI values: amount × CPI end ÷ CPI start.
What is Inflation Calculator?
Shows the effect of inflation in two ways: what something costing a given amount today will cost in the future, and what a sum of money will be worth in today's terms. A CPI mode adjusts an amount between two consumer-price-index values and derives the average annual rate.
How to use Inflation Calculator
- Choose Using an annual rate or Using CPI values.
- Enter the Amount.
- Enter the inflation rate and number of years, or the start and end CPI (and optionally the years between them).
Example
100 at 3% for 10 years
Future cost 134.39; purchasing power 74.41; cumulative inflation 34.39%
When to use Inflation Calculator
Use it for salary negotiations, long-term budgets and comparing prices across years. Real inflation varies each year, so a constant rate is a simplification.
How Inflation Calculator works
With a rate: future cost = amount × (1 + rate)^years and purchasing power = amount ÷ (1 + rate)^years; cumulative inflation = (1 + rate)^years − 1. With CPI values: adjusted amount = amount × CPI end ÷ CPI start, and the average annual rate = (CPI end ÷ CPI start)^(1 ÷ years) − 1. The tool does not contain historical CPI data; enter the official index values for your country.
Common Use Cases
- Estimating future tuition or rent
- Comparing an old salary with today's
- Adjusting a contract amount with official CPI
- Explaining loss of purchasing power
FAQs
Where do I find CPI values?
National statistics offices publish them, e.g. the BLS in the United States or Eurostat (HICP) in the EU.
Why are future cost and purchasing power not symmetric?
They divide or multiply by the same factor, so a 34.39% price rise corresponds to a 25.59% loss of purchasing power.
Can I enter deflation?
Yes, negative rates are accepted.