United States
Inflation calculator
Money tends to buy less as the years pass, and this tool puts numbers on that. Enter an amount, the inflation rate you expect, and how many years to project, and it works out both sides of the coin: what a given purchase will cost in future, and how much spending power a fixed sum of money will have lost by then. It is useful for sense-checking a long-term savings target, judging whether a future salary keeps pace with prices, or seeing how far cash erodes if it sits idle.
How it works
- Enter an amount in current money and the annual inflation rate you want to assume.
- Set the number of years to look ahead.
- For future cost, the amount is multiplied by (1 + rate) raised to the power of the years.
- For future spending power, the amount is divided by that same factor, showing what it would buy in current terms.
future cost = amount x (1 + r)^n; future power = amount / (1 + r)^n
To project a future price, the amount is multiplied by one plus the annual rate, raised to the number of years. To show lost spending power, the same amount is divided by that factor, telling you what the money would buy in current terms. Because the factor is raised to a power, the effect builds on itself year after year rather than adding a flat slice.
- amount
- a sum in today money
- r
- annual inflation rate as a decimal
- n
- number of years projected
Inflation rates for reference
| Bank of England target | 2% | measured on CPI |
| European Central Bank target | 2% | over the medium term |
| UK CPI peak, October 2022 | 11.1% | a 41-year high |
| Rule-of-72 doubling at 3% | ≈ 24 years | for prices to double |
Worked example
1,000 at 3 percent inflation over 10 years: something costing 1,000 now would cost about 1,344 then, while a 1,000 note kept under the mattress would buy only around 744 worth of goods. Higher rates widen both gaps quickly.
Key facts
- At a steady 3 percent, prices roughly double every 24 years, following the rule of 72.
- Inflation compounds, so each year stacks on an already higher base rather than the original figure.
- A fixed sum of cash loses spending power every year that prices rise, even sitting untouched.
- The gap between 2 and 4 percent looks small yearly but becomes large across a working lifetime.
Tips
- Try two or three rates rather than one, since future inflation is genuinely uncertain.
- For a realistic figure, check your national statistics office for recent and forecast inflation.
- When judging a long-term savings target, inflate the goal so it still buys what you intend.
- To see money beat inflation rather than just erode, use a compound interest or savings tool instead.
A sum of 1,000 at 3% inflation
| Years | Future cost | Future spending power |
|---|---|---|
| 5 | 1,159 | 863 |
| 10 | 1,344 | 744 |
| 20 | 1,806 | 554 |
| 30 | 2,427 | 412 |
Frequently asked questions
What inflation rate should I assume?+
Many central banks target roughly 2 percent a year, though several recent years ran well above that in many countries. Trying two or three rates gives you a sensible range rather than a single guess.
Is this the same as investment growth?+
No. This shows price changes alone. To see money grow ahead of inflation, use the compound interest or savings goal calculators, which add returns rather than erode value.
Does it use my country's actual inflation?+
No. The rate is whatever you enter, so it is not tied to any official index. For a realistic figure, check your national statistics office for recent and forecast inflation.
Why do small rate changes matter so much over time?+
Inflation compounds, so each year applies to an already-inflated figure. Over a decade or two, the difference between 2 and 4 percent becomes large rather than double.
Last updated: 2026
This is an estimate for general guidance, not financial, tax, legal or medical advice. Figures can change and individual circumstances vary. Always confirm with the official sources listed before making decisions.
- This is general information, not financial advice.
- Uses a constant assumed rate; real inflation varies year to year and differs by country.
- Does not model investment returns or interest.
Reviewed by Vikas Dulgunde.