Inflation Calculator

A dollar is not a fixed unit of value. It is a claim on goods and services whose price changes every year, and over a decade those changes compound into something unrecognizable. The $100 grocery bill of 2015 costs meaningfully more today — not because groceries changed, but because the dollar shrank.

This calculator translates dollars across time. Pick an amount and a year from 2015 onward, and it converts the figure into August 2026 dollars using the Consumer Price Index for All Urban Consumers (CPI-U), the Bureau of Labor Statistics’ headline measure of inflation. The result is what that money would have to be today to buy the same basket of goods.

It sits in our Cents & Sense alongside the income tax estimator — pair them to see what your after-tax pay actually bought in prior years.

What it measures

The calculator measures the change in the purchasing power of the US dollar between any year from 2015 to 2025 and August 2026, the latest month with published CPI data. It outputs the equivalent amount in August-2026 dollars, the cumulative percentage change in the price level, and the implied loss of purchasing power — the share of a dollar’s buying capacity that has evaporated since the starting year.

The underlying index is CPI-U (1982–84 = 100), reported here as annual averages: 237.017 for 2015, rising to 321.943 for 2025, with the August 2026 reading at 334.980. One quirk of the official record: October 2025 was not collected due to a lapse in federal appropriations.

How it works

The conversion is a single ratio. The adjusted amount equals your starting amount multiplied by the latest CPI divided by the starting year’s CPI: amount × (334.980 / CPI_from). The cumulative percentage change is that same ratio minus one, expressed as a percent. The purchasing-power loss is one minus the starting CPI divided by the latest CPI — it answers the inverse question: how much of a dollar’s buying power has been lost.

Because the inputs are annual averages through 2025 and a single monthly reading for 2026, the comparison mixes two slightly different series — standard practice for “as of today” inflation conversions, and disclosed so you know exactly what the number rests on.

Each input, explained

Dollar amount. Any figure in the starting year’s dollars — a salary, a house price, a tuition bill. Defaults to $100 for quick comparisons.

From year. The year your figure belongs to, from 2015 through 2025. Each option shows its annual-average CPI value so the index behind the math is never hidden. Defaults to 2015.

To. Fixed at the latest available reading: August 2026, CPI 334.980. Inflation calculators are only as fresh as their data, so the endpoint is labeled with its month rather than a vague “today.”

Worked example

Take $100 in 2015 dollars. The 2015 annual-average CPI was 237.017 and the August 2026 reading was 334.980, so the conversion is $100 × (334.980 / 237.017) = $100 × 1.413316 = $141.33. Cumulative price change: 41.33%. Purchasing-power loss: 1 − (237.017 / 334.980) = 29.24% — a dollar from 2015 buys about 29% less than it did.

Put differently: to stand still in real terms from 2015 to August 2026, a salary, a rent, or a savings balance needed to grow 41% in nominal terms. Anything that grew less lost ground. That is the quiet arithmetic behind a decade of cost-of-living debates.

Limitations

CPI-U tracks a national average basket for urban consumers; your personal inflation rate depends on what you actually buy. Housing-heavy households in high-cost metros have felt more inflation than the index shows; the index also substitutes and quality-adjusts in ways that can understate lived experience.

The calculator uses annual averages for past years and a single month for the endpoint, so short-run moves around August 2026 can shift the reading slightly. And it measures price change, not welfare — it says nothing about quality improvements, new products, or what the money was spent on. For the mechanics of how inflation is measured and why markets hang on every release, see How Inflation Actually Works — and Why Markets Obsess Over It.

FAQs

What is CPI-U?
The Consumer Price Index for All Urban Consumers, published monthly by the Bureau of Labor Statistics. It tracks the average price change of a fixed basket of goods and services bought by roughly 93% of the US population, indexed to 1982–84 = 100.

Why does the calculator use annual averages for past years but a monthly figure for now?
Annual averages smooth out monthly noise when comparing whole years, while the most recent published month gives the freshest endpoint. Mixing them is standard for up-to-date conversions; the alternative — waiting for a full 2026 average — would leave the answer a year out of date.

What happened to the October 2025 CPI reading?
It was not collected because of a lapse in federal appropriations. The annual average for 2025 is computed from the months that were collected.

Does this show my personal inflation rate?
No — it shows the national average. If rent dominates your budget, your rate is likely higher; if you are a homeowner with a fixed mortgage, likely lower. The CPI weights reflect average spending, not yours.

Is a 41% cumulative rise over eleven years a lot?
It averages roughly 3.2% a year — above the Federal Reserve’s 2% target, and heavily front-loaded by the 2021–2023 surge. The number looks large because compounding is doing quiet work: small annual rates stack into large decade-long moves.

Can I use this to adjust a contract or salary?
It is a fine starting point for a cost-of-living conversation, but formal escalation clauses usually name a specific CPI series and reference period. Check the contract language before applying any number.

This calculator is for education only and is not financial advice. Index values come from the Bureau of Labor Statistics via published CPI tables; always confirm the latest release before using the figures for any formal purpose.