Methods
How the Personal Inflation Calculator works, in short. Tap a question to open it.
What does this tool do?
The official consumer price index (CPI) tracks how prices change for the average household. Your spending isn’t average. This tool lets you set your own spending shares, then shows the year-over-year inflation rate that results (“Your CPI”) next to the official headline CPI.
How is “Your CPI” calculated?
- We use the Bureau of Labor Statistics’ (BLS) own spending categories and price indexes, with your shares in place of BLS’s.
- It is built up from the most detailed categories. BLS’s published totals for broader groups are not used; the official headline is drawn only for comparison.
- Your shares are reset every December, as BLS does with its own basket.
- At the default shares it tracks the official number closely: since 1993 the annual rate differs by 0.26 percentage points on average (largest single month: 2.12), and in January to August 2026 by no more than 0.24. We haven’t traced every difference.
Where does the data come from?
- Prices: BLS Consumer Price Index for All Urban Consumers (CPI-U), U.S. city average, not seasonally adjusted. download.bls.gov/pub/time.series/cu
- Default spending shares: BLS relative importance (each category’s share of the average household’s spending), December 2025. bls.gov/cpi/tables/relative-importance/2025.htm
- Data current through the latest month in the data.
How is take-home pay estimated?
Enter a state and income and the tool estimates your take-home pay. It never changes your shares or the chart.
- Included: federal and state income tax, Social Security and Medicare, and statewide payroll programs such as California’s disability insurance and paid family leave.
- Assumed: single filer, tax year 2026, standard deduction. If a state hasn’t published 2026 figures, we use its latest year.
- Left out: local income taxes, credits, dependents, itemized deductions, retirement contributions, non-wage income.
This is an estimate of annual tax, not what your employer withholds; per-paycheck figures assume 26 biweekly pays. Rules: IRS Revenue Procedure 2025-32, the Social Security Administration, state revenue departments.
What are the limits?
- Homeowners: BLS measures housing costs for owners by what their home would rent for, not by mortgage payments.
- Four categories BLS currently isn’t publishing (household operations, domestic services, repair of household items, legal services), because too few prices were collected. Their share is spread across related categories.
- October 2025 is missing: the federal shutdown stopped BLS price collection from October 1 to November 12, and it can’t go back. BLS also says rent-based housing figures for November 2025 to March 2026 aren’t comparable with other periods.
- The chart starts in January 1993, when all eight major spending groups have price data. Before 1998, about a quarter of the basket lacks its own price series and is filled in from related categories.
Is my information private?
We count visits anonymously, without cookies, using Cloudflare Web Analytics. Your state, income and savings never leave your browser: the calculations run on your device, and your settings are remembered only in your browser’s own storage.