Inflation Calculator
Runs locally in your browser. Nothing leaves your device.Calculate how constant inflation or deflation changes prices and purchasing power over time.
Calculate inflation and purchasing power
Example assumption – not a current or country-specific rate.
Equivalent price after the period
$121.90
Inflation
- Purchasing power of the same amount
- $82.03
- Cumulative price change
- 21.9%
- Purchasing-power loss
- 17.97%
- Price factor
- 1.219×
Yearly progression and formula
| Period | Equivalent price | Purchasing power |
|---|---|---|
| 0 months | $100.00 | $100.00 |
| 1 years, 0 months | $102.00 | $98.04 |
| 2 years, 0 months | $104.04 | $96.12 |
| 3 years, 0 months | $106.12 | $94.23 |
| 4 years, 0 months | $108.24 | $92.38 |
| 5 years, 0 months | $110.41 | $90.57 |
| 6 years, 0 months | $112.62 | $88.80 |
| 7 years, 0 months | $114.87 | $87.06 |
| 8 years, 0 months | $117.17 | $85.35 |
| 9 years, 0 months | $119.51 | $83.68 |
| 10 years, 0 months | $121.90 | $82.03 |
Constant inflation is a model assumption, not a forecast or financial advice.
How it works
- 1
Choose a calculation mode
Decide whether you want to project prices, work out the annual rate, or calculate the time to a target price.
- 2
Enter the values for the chosen mode
Depending on the mode, enter the amount, starting and ending price, rate, or target price and the period.
- 3
Review the result and progression
Review the main result and, optionally, the year-by-year progression and the formula used.
Good to know
The inflation calculator offers three calculation modes instead of just one formula: project future prices and purchasing power at an assumed inflation rate, work out the average annual rate implied by a known starting and ending price, or calculate how long it takes to reach a target price at a given rate.
Calculation runs locally in the browser. Consumer price indices are averages; personal spending patterns can differ materially, and the assumed rate is an example, not an official forecast.
Typical use cases
Project future prices and purchasing power
Enter an amount, an assumed inflation rate, and a period to see the future price and the corresponding purchasing power of today's money.
Work out the real price increase from two prices
Enter a known starting and ending price to calculate the average annual rate - useful for determining the actual increase of a specific product or rent retrospectively.
Calculate time to a target price
Enter a target price and an assumed rate to see after how many years and months that price would be reached at a constant inflation rate.
Tips for better results
Treat the assumed rate clearly as an assumption
The entered inflation rate is an example value, not an official forecast. Test several rates to get a range instead of a single figure.
Distinguish personal spending from the consumer price index
Official inflation rates are averages across a basket of goods. Rent, energy, or specific groceries may become more expensive faster or slower for you personally.
Features
Three calculation modes
Switch between price/purchasing-power projection, implied annual rate, and time to target price.
Nominal and real values kept separate
Price factor, purchasing-power loss, and today's purchasing power are clearly distinguished rather than mixed together.
Yearly progression and formula visible
An expandable section shows the year-by-year progression and the formula used for full transparency.
Frequently asked questions
Which inflation rate should I enter?
The tool does not suggest a current or country-specific rate. Use an official statistic for your country or test several values to see a range.
How is the annual rate calculated from two prices?
The tool calculates the constant annual rate that turns the starting price into the ending price over the given period, including a power factor for partial years.
What exactly does purchasing-power loss mean?
It shows how much less a fixed amount of money can actually buy after the assumed inflation over time, expressed as a percentage or as today's equivalent value.
More tools
Looking for another tool?
Every tool runs locally in your browser – no sign-up, no upload, and it works offline.