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Free Inflation Calculator

See how inflation reshapes money over time. Enter a dollar amount, an annual inflation rate and a number of years to learn both the future cost of the same purchase and what a future amount is worth in today's dollars, with a year-by-year breakdown.

Future cost in 10 yr
$134.39

What the same purchase costs after inflation.

Worth today (buying power)
$74.41

What that future amount is worth in today's dollars.

Cumulative inflation over 10 years: 34.39%. Each $1 today buys what $0.74 buys after inflation.

Year-by-year breakdown

YearFuture costWorth today
1$103.00$97.09
2$106.09$94.26
3$109.27$91.51
4$112.55$88.85
5$115.93$86.26
6$119.41$83.75
7$122.99$81.31
8$126.68$78.94
9$130.48$76.64
10$134.39$74.41

Estimate only. This calculator provides estimates based on the values you enter and the formula shown. It is not financial advice and may not reflect every fee, tax, or lender requirement. Check figures with a qualified professional before making financial decisions.

Quick answer

Inflation compounds, so the future cost of something that costs an amount today is amount × (1 + r/100)^Y, where r is the annual inflation rate as a percent and Y is the number of years. The reverse — what a future amount is worth in today's money — divides instead: amount ÷ (1 + r/100)^Y. For example, $100 at 3% inflation will cost about $134.39 in 10 years, and $100 received 10 years from now is worth only about $74.41 today.

Formula & method

The calculator treats inflation as compound growth at a constant annual rate. It first converts the rate r% to a decimal factor (1 + r/100). To project how much a purchase will cost later, it multiplies your amount by that factor once for each year: future cost = amount × (1 + r/100)^Y. To find purchasing power instead — what a fixed future sum buys in today's dollars — it divides by the same factor: today's value = amount ÷ (1 + r/100)^Y. The year-by-year table applies the factor one year at a time so you can see the running cost and running buying power for every year up to Y. All math runs in your browser; nothing is sent to a server.

Examples

Example 1: $100 at 3% for 10 years
Input
Amount $100, rate 3%, 10 years
Result
Future cost ≈ $134.39; today's value of $100 in 10 years ≈ $74.41
Why
(1 + 3/100) = 1.03, and 1.03^10 = 1.343916. Future cost = 100 × 1.343916 = $134.39. Buying power of a future $100 = 100 ÷ 1.343916 = $74.41. Cumulative inflation over the decade is 34.39%.
Example 2: $50,000 at 4% for 20 years
Input
Amount $50,000, rate 4%, 20 years
Result
Future cost ≈ $109,556.16; today's value ≈ $22,819.35
Why
1.04^20 = 2.191123. Future cost = 50,000 × 2.191123 = $109,556.16, so the same purchase more than doubles in price. A future $50,000 is worth 50,000 ÷ 2.191123 = $22,819.35 in today's dollars — less than half.
Example 3: $1,000 at 2.5% for 30 years
Input
Amount $1,000, rate 2.5%, 30 years
Result
Future cost ≈ $2,097.57; today's value ≈ $476.74
Why
1.025^30 = 2.097568. Future cost = 1,000 × 2.097568 = $2,097.57 — prices roughly double in about 28 years at 2.5% (the Rule of 72: 72 ÷ 2.5 ≈ 28.8). A future $1,000 is worth only 1,000 ÷ 2.097568 = $476.74 today.

When to use this tool

  • Estimating how much a future expense — college, a car, a wedding, retirement living costs — might cost in tomorrow's dollars.
  • Understanding how much purchasing power cash loses if it sits idle instead of earning a return.
  • Comparing a salary, pension, or fixed payment across years to see whether it keeps up with rising prices.
  • Setting a realistic savings target by inflating today's cost forward to the year you will actually spend it.

Common mistakes

  • Confusing the two questions. "What will it cost?" multiplies by (1 + r/100)^Y; "What is it worth today?" divides by it. Mixing them up flips the answer.
  • Adding inflation linearly instead of compounding. 3% for 10 years is not 30% — it compounds to 34.39% because each year's increase is applied on top of the previous year's higher price.
  • Entering the rate as a decimal. Type 3 for 3%, not 0.03. The tool divides by 100 for you.
  • Assuming a single fixed rate is exact. Real inflation varies year to year; a constant rate is a clean estimate, not a guaranteed forecast.
  • Forgetting that wages, savings, and investments may also grow. Inflation erodes idle cash fastest; money that earns a return can offset some or all of it.

Frequently asked questions

What is the formula for inflation over time?

Future cost = amount × (1 + r/100)^Y, where r is the annual inflation rate as a percent and Y is the number of years. To find what a future amount is worth today instead, divide: today's value = amount ÷ (1 + r/100)^Y. Both treat inflation as compound growth, so each year builds on the last.

What inflation rate should I use?

Many people use a long-run average of about 2–3% for the U.S. dollar, which is near the Federal Reserve's 2% target and the historical CPI average. You can enter any rate you expect. Because future inflation is uncertain, try a few rates to see a realistic range rather than a single guaranteed number.

What is the difference between future cost and buying power?

Future cost answers "how many dollars will this same purchase need later?" and grows with inflation. Buying power answers "what is a fixed future amount worth in today's dollars?" and shrinks with inflation. They are mirror images: one multiplies by the inflation factor, the other divides by it.

How long until prices double from inflation?

Use the Rule of 72: divide 72 by the inflation rate. At 3%, prices roughly double in 72 ÷ 3 = 24 years; at 4%, in about 18 years; at 2%, in about 36 years. It is an approximation, but it is close for the low single-digit rates typical of inflation.

Does this calculator account for taxes, wages, or investment returns?

No. It isolates the effect of inflation alone on a single amount. It does not model income growth, investment returns, or taxes. To see purchasing power after investing, compare these results with a compound-interest or investment-return calculator using your expected rate of return.

Is a constant inflation rate realistic?

It is a simplification. Actual annual inflation rises and falls — some years above your rate, some below. A single constant rate gives a clean, transparent estimate that is useful for planning, but it is not a precise prediction. For accuracy over long periods, treat the result as a central estimate and test higher and lower rates.

Sources & references

External references open in a new tab. We are independent and not affiliated with these organizations.

Disclaimer

This calculator provides estimates based on the values you enter and the formula shown. It is not financial advice and may not reflect every fee, tax, or lender requirement. Check figures with a qualified professional before making financial decisions.

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  • ✓ Runs entirely in your browser — nothing is uploaded.
  • ✓ Formula and method shown above
Last updated: How we calculateReport a correctionDisclaimer

Provided “as is” for general information only — results may be inaccurate, so verify before you rely on them. No warranty; use at your own risk.

Built and reviewed by HIFreeTools against the formula shown above and any authoritative references cited on this page. See our methodology and editorial standards.

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