Inflation Calculator

See how inflation erodes purchasing power and calculate the real value of money over time.

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Amount

Annual Inflation Rate (%)

Number of Years

Calculate

Future Value

Original Amount

Purchasing Power Lost

Cumulative Inflation

Avg Annual Loss

Year	Value	Cumul. Inflation	Purchasing Power

Find out how much a sum of money will be worth in the future after inflation, or what a current amount was worth years ago, using your own assumed annual inflation rate.

How It Works

How Inflation Calculator Works

The calculator applies the same compounding formula used for investment growth, just run in the direction of rising prices. For a future value, it computes FV = amount × (1 + r)^t, where r is your annual inflation rate and t is the number of years — so a fixed dollar amount needs to grow by that factor just to buy the same goods later. For a past value, it runs the formula in reverse: PV = amount ÷ (1 + r)^t, showing what today's amount was equivalent to some years back.

Cumulative inflation over the full period is (1 + r)^t − 1, expressed as a percentage, which is always larger than simply multiplying the annual rate by the number of years because inflation compounds year over year, just like interest.

The year-by-year table repeats this calculation for every year from 1 up to your chosen horizon (capped at 50 rows), showing the running cumulative inflation and the resulting loss of purchasing power at each step, not just the final year.

Worked Example

See It In Action

With the default inputs — $1,000 at 3% annual inflation over 10 years, solving for future value — the calculator returns 1,000 × 1.03^10 ≈ $1,343.92. That means $343.92 of purchasing power has effectively been added just to keep pace with prices, and cumulative inflation over the decade works out to about 34.39%, even though the annual rate never exceeded 3%.

Real-World Use Cases

Who Uses Inflation Calculator and Why

Finding out how much a fixed dollar amount today will need to grow to just keep pace with prices years from now.
Working out what a past salary, price, or savings goal is equivalent to in today's dollars.
Stress-testing a financial plan against a higher assumed inflation rate than the historical average.
Seeing cumulative inflation over a chosen time horizon rather than just the ending future or past value.

Common Mistakes

Mistakes to Avoid

Assuming cumulative inflation over N years is simply the annual rate times N — because inflation compounds, the example shows 3% annual inflation compounding to roughly 34.39% over 10 years, well above a flat 30%.
Confusing future value mode with past value mode — future value asks what you'll need later to match today's buying power, past value asks what today's amount was worth years ago; picking the wrong mode reverses the answer.
Treating the result as based on real historical CPI data — the calculator applies a constant, user-supplied rate across every year rather than pulling actual historical inflation figures.

Pro Tips

Tips for Best Results

Use the year-by-year table, not just the final-year figure, if you want to see how purchasing power erodes gradually rather than all at once.
Try a higher-than-average rate (above the commonly used 2-3% long-run US figure) to see how a more inflationary scenario would affect your numbers.

Troubleshooting

Fixing Common Problems

My cumulative inflation percentage looks bigger than I expected for the annual rate I entered. — This is expected — inflation compounds year over year rather than applying to a fixed base amount, so cumulative inflation over a decade is always higher than simply multiplying the annual rate by the number of years.

Glossary

Terms Explained

Cumulative inflation: The total compounded price increase over a full time period, calculated as (1 + rate)^years − 1, expressed as a percentage.

Purchasing power: What a fixed amount of money can actually buy, which erodes over time as prices rise under inflation.

FAQ

Frequently Asked Questions

What's the difference between future value and past value here?

Future value tells you how much money you'd need down the road to have the same buying power as an amount today. Past value works backwards, showing what today's amount was equivalent to at some point in the past — useful for comparing old prices or salaries to today's dollars.

Why is cumulative inflation over 10 years more than 10 times the annual rate?

Because inflation compounds — each year's price increase applies on top of the previous year's already-higher prices, not on the original amount. That's why 3% annual inflation adds up to roughly 34% over a decade instead of a flat 30%.

What inflation rate should I use?

A commonly used long-run average for the US is around 2–3% annually, though actual year-to-year inflation varies significantly. Use a higher rate to stress-test a plan against a more inflationary environment.

Does this calculator account for actual historical CPI data?

No — it applies a constant rate you specify across every year, rather than pulling real historical Consumer Price Index figures. It's a projection tool for a chosen assumption, not a lookup of actual past inflation.