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Inflation Calculator

Convert dollars between years with official CPI-U annual averages from 1913 to 2025 and the latest May 2026 CPI value.

When to use this

Use it when an old price needs today context

Compare salaries, rents, prices, budgets, allowances, tuition, subscriptions, old receipts, and historical amounts using the same CPI formula.

Default result

$100.00 in 2000 has the same CPI buying-power as $194.61 in May 2026.

Convert a dollar amount

Use annual average CPI for years, or compare a past year to the latest available month.

How we calculate it

Equivalent amount = original amount x target CPI / start CPI. Cumulative inflation = (target CPI / start CPI - 1) x 100. Annualized inflation uses the elapsed years between the CPI reference points.

Result interpretation

What the inflation number means

Equivalent dollars are not profit

The result only converts buying power. It does not include taxes, investment returns, wage growth, or changes in product quality.

CPI is broad, not personal

CPI-U tracks a broad urban consumer basket. Your own basket can move faster or slower than the national index.

Annualized rate smooths the path

The annualized rate turns a whole period into one average yearly pace. Individual years can still be much higher or lower.

Worked example: $100 in 2000 to May 2026

The BLS annual average CPI-U for 2000 is 172.2. The latest monthly CPI-U used here is May 2026 at 335.123.

Equivalent amount = $100 x 335.123 / 172.2 = $194.61. The cumulative price-level change is (335.123 / 172.2 - 1) x 100 = 94.6%.

Using the annual-average midpoint for 2000 and the May 2026 month midpoint gives about 25.875 years. The annualized inflation rate is (335.123 / 172.2)^(1 / 25.875) - 1 = 2.6% per year.

How much is money from the past worth today?

Divide the target CPI by the start CPI, then multiply the original amount by that ratio. If the ratio is 2.0, prices are roughly double the start-period level.

How do I calculate cumulative inflation between two years?

Cumulative inflation equals target CPI divided by start CPI, minus 1, then multiplied by 100. This calculator uses annual averages for full-year comparisons.

What is the latest CPI value in this calculator?

The latest embedded monthly value is May 2026 CPI-U at 335.123 from the BLS Public Data API. The latest full-year annual average is 2025 CPI-U at 321.943.

Why does CPI differ from cost of living?

CPI is a national price index. Cost of living can include local housing, taxes, transportation, lifestyle, income, household size, and benefits, so a city-level comparison needs a different dataset.

How to make a shareable inflation result

Use the copy button to share the amount, years, equivalent value, CPI ratio, and a Useful Atlas link. That lets someone else calculate their own amount without needing your exact scenario.

Reference data

Official CPI source table

Topic Value used Source Date Note
CPI series CUUR0000SA0, CPI-U, U.S. city average, all items, not seasonally adjusted BLS Public Data API As of June 19, 2026 Annual values use BLS annual average period M13. Verify current data and API terms at the source.
Latest monthly CPI used May 2026 CPI-U = 335.123 BLS CPI news release As of June 19, 2026 The latest month is used only when the target is set to May 2026. Annual comparisons use annual average CPI.
Latest annual CPI used 2025 annual average CPI-U = 321.943 BLS Public Data API As of June 19, 2026 This is the newest full-year annual average in the embedded table.

FAQ

What CPI measure does this inflation calculator use?

It uses BLS series CUUR0000SA0: Consumer Price Index for All Urban Consumers, U.S. city average, all items, not seasonally adjusted.

Why does the calculator use annual averages for past years?

Annual average CPI is a stable way to compare calendar years. It avoids choosing one arbitrary month unless the target is explicitly set to the latest available month.

Can I compare May 2026 with a prior year?

Yes. The latest option uses May 2026 CPI-U at 335.123, while the start year uses that year annual average. The annualized rate therefore uses midpoint timing as an approximation.

Is this the same as personal inflation?

No. CPI-U is a broad national price index. Your own inflation can differ because housing, transportation, food, taxes, health care, and local prices may move differently.

Why do some old years show deflation?

The CPI can move down over some periods. If the target CPI is lower than the start CPI, the equivalent amount is lower and the cumulative change is negative.

Can I share the result?

Yes. The copy button creates a short text result with the amount, years, CPI values, and a Useful Atlas link so another person can calculate their own comparison.

Decision path

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