What does Inflation Calculator do?
Inflation calculator: find what something will cost in future, what money will be worth in today’s terms, or the average inflation rate between two prices.
- Price
- Free
- Account
- Not required
- Processing
- Entirely in your browser; your data and files are not uploaded
- Works on
- Any modern browser on desktop, tablet or phone
- Category
- Financial Calculators
How to use the inflation calculator
- Choose what to find: future cost, purchasing power, or the inflation rate between two prices.
- Enter the amount (or the earlier and later prices) and the number of years.
- For future cost and purchasing power, enter an average annual inflation rate.
- Read the result, the total price rise, the doubling time and the year by year table.
Worked example
$100 at 3% inflation for 10 years
Something costing $100 today would cost $100 × 1.0310 = $134.39 in 10 years, a 34.39% rise. Seen the other way, $100 received in 10 years would buy what $74.41 buys today. At 3% a year prices double in about 23.4 years. Entering $100 and $134.39 over 10 years gives back an average rate of 3.00%.
How it works
Future cost = C × (1 + i)t. Purchasing power in today’s money = A ÷ (1 + i)t. Average inflation between two prices = (later ÷ earlier)1/t − 1. Doubling time = ln 2 ÷ ln(1 + i). The rate i is the average annual rate you enter, compounded yearly.
Assumptions
- One constant average rate applies every year; the default 3% is an example, not a forecast.
- No official price index data is built in. For historical prices use your country’s official consumer price index.
Frequently asked questions
What inflation rate should I use?
For planning, many people use their central bank’s target or a recent long-run average for their country. For past periods, look up the official consumer price index from the national statistics agency (for example the US Bureau of Labor Statistics or the Australian Bureau of Statistics).
What is purchasing power?
How much a sum of money can buy. With inflation, the same amount buys less over time, so future dollars are worth less in today’s terms.
Why doesn’t 3% for 10 years equal 30%?
Inflation compounds: each year’s rise applies to prices that already rose, so 3% a year for 10 years is a 34.39% total rise.
Limitations
- Uses a single rate you choose, not official CPI history.
- Individual prices (rent, food, wages) can rise much faster or slower than average inflation.