Inflation Calculator: Future Cost and Buying Power
Future cost, today's value and the rule of 72 at an inflation rate you choose.
You choose the rate: this calculator has no built-in price index. A central bank target (often 2%) or your country's recent average is a reasonable start.
Use via API
Inflation at a steady annual rate: what an amount will cost in the future, or what a future amount is worth in today's money, plus purchasing power lost and doubling time. Send JSON, get JSON back.
POST https://pithlab.com/api/v1/tools/inflation-calculator
curl https://pithlab.com/api/v1/tools/inflation-calculator \
-H "Authorization: Bearer $PITHLAB_KEY" \
-H "Content-Type: application/json" \
-d '{"mode":"future","amount":1000,"rate":3,"years":10}'About the Inflation Calculator
See what something will cost in the future and what money will be worth, at an inflation rate you choose, plus how long until prices double by the rule of 72.
How to use the Inflation Calculator
- Choose whether you're starting from an amount today or an amount in the future.
- Enter the amount, the average yearly inflation rate you expect (for example a central bank target or a recent average), and the number of years.
- Read the future cost or today's value, how much buying power is lost, and how long it takes prices to double.
Examples
Input
100 today, 3% a year, 10 years
Output
At 3% a year, 100.00 today will cost 134.39 in 10 years, and 100.00 then will buy what 74.41 buys today.
Input
50,000 in the future, 2.5% a year, 20 years
Output
At 2.5% a year, 50,000.00 in 20 years is worth 30,513.55 in today's money.
Frequently asked questions
Where does the inflation rate come from?
You supply it. This calculator doesn't contain historical price data, so it works with any average annual rate you enter, such as a central bank's 2% target, a forecast, or the past average from your country's statistics office.
What is the rule of 72?
A shortcut for how long it takes something growing at a steady rate to double: divide 72 by the rate. At 3% inflation prices double in about 72 ÷ 3 = 24 years (23.4 exactly), which also means money loses half its buying power in that time.
Why is the result different from an online CPI calculator?
CPI calculators use the actual price index for specific years, which rises unevenly. This one assumes the same rate every year, compounded, so it is best for planning ahead or for a rough look back when you know the average rate.
Can I use a negative rate?
Yes. A negative rate models deflation: prices fall, so future costs come out lower and money gains buying power. The rule of 72 only applies to positive rates.