Inflation Calculator
See what an amount of money will be worth in the future, and how much purchasing power it loses to inflation.
Formula and sources updated · Data sources · 1View algorithm, constants and default inputs (JSON)
Comparison
About this calculator
Project a fixed amount using the annual inflation rate you enter and annual compounding. This is a mathematical scenario, not a forecast: actual inflation varies over time, and the calculator does not use a current CPI series or account for investment returns, taxes or fees.
Worked example
calculated with the default values below
Amount today 1,000 $ · Average annual inflation 3 % · Number of years 10 years Equivalent future cost 1,343.92 $ · Future buying power of the amount 744.09 $ · Purchasing power lost 25.59 %
Data sources
Disclaimer
These calculators give estimates for general information only. They are not financial, tax or investment advice and do not take your personal circumstances into account. Before borrowing, investing or filing, confirm the numbers with a qualified adviser in your jurisdiction.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
F = A × (1 + i ÷ 100)^y ; P = A ÷ (1 + i ÷ 100)^y ; L = (1 − P ÷ A) × 100
- A
- current amount
- i
- annual inflation rate (%)
- y
- years
- F
- future cost
- P
- future purchasing power
L is the percentage of purchasing power lost; a constant annual inflation rate is assumed.
Frequently asked questions
Which inflation rate should I enter?
For a single country, the consumer price index for the period you care about. For long horizons, a long-run average is more realistic than the latest reading, because a single year's spike distorts a thirty-year projection badly. If you are comparing two countries' currencies, use the differential between them rather than either one alone.
Why does a small rate matter so much over decades?
Because it compounds against you. At three percent a year, prices roughly double in twenty-four years, so money left idle loses about half its purchasing power within a working lifetime, and more than two thirds over forty years. The effect is easy to dismiss in year one and impossible to ignore in year thirty.