The eight categories of CPI.
Headline CPI isn't one number — it's a weighted blend of eight major expenditure categories, each with its own dynamics. Understanding the components is the difference between reading the headline and understanding what actually drove it.
The Bureau of Labor Statistics groups the consumer market basket into eight major expenditure categories. Each is built from hundreds of more specific item strata — over 200 in total — sampled monthly from more than 23,000 retail outlets across 75 U.S. urban areas. The weights you see below come from the Consumer Expenditure Survey, the BLS's continuous survey of household spending. Beginning in 2023, those weights are updated annually rather than every two years, reflecting how quickly consumer behavior can shift.
Food & Beverages
Groceries (food at home) and dining out (food away). Captures everything households eat or drink, plus alcoholic beverages.
View data →Energy
Motor fuel, electricity, natural gas, fuel oil. The single most volatile component.
View data →Housing & Shelter
Rent, owners' equivalent rent, lodging, household furnishings, household operations, utilities — the largest CPI bucket.
View data →Transportation
Vehicles new and used, motor fuel, insurance, maintenance, public transit, airfares.
View data →Medical Care
Health insurance, prescription drugs, hospital services, professional services.
View data →Apparel
Clothing for men, women, children, plus footwear. Heavily influenced by import prices and seasonal cycles.
View data →Education & Communication
Tuition, school fees, books, telephone and internet, computer software and services.
View data →Recreation
Video and audio, sporting goods, recreation services, pets, tobacco, personal care.
View data →How BLS calculates the weights
Every CPI release relies on a set of relative importance values — the share of total household spending that each category, sub-category, and item represents. These weights determine how much each price change contributes to the headline number.
Weights come from the Consumer Expenditure Survey (CES), a rolling survey conducted by the Census Bureau on behalf of BLS. The CES has two components: a quarterly interview survey that captures large and recurring expenditures (rent, insurance, vehicles), and a diary survey that captures small frequent purchases (groceries, gasoline, personal care).
Until 2022, BLS used two years of expenditure data lagged about two years behind the current period — for instance, the 2022 weights reflected 2019–2020 spending. Beginning with the January 2023 release, BLS moved to annual reweighting using a single year of CES data. The change reduces the time lag and helps the index keep up with shifts in consumer behavior, particularly post-pandemic shifts toward services.
It's worth understanding what relative importance is and isn't. It is the share of the basket at a fixed point in time. It is not a forecast — it doesn't predict how households will spend next year. As prices in one category rise faster than another, the effective weight of that category in the index drifts higher (a phenomenon called "weight effects"). The annual reweighting catches up to those drifts.
Sub-categories that matter
Within the eight majors, a handful of sub-categories carry outsized influence:
- Shelter (~35% of the total basket) — rent of primary residence + owners' equivalent rent of primary residence
- Food at home (~8%) — supermarket groceries
- Food away from home (~5%) — restaurant meals
- Motor fuel (~3%) — gasoline (90%+) and other motor fuels
- New & used vehicles (~6%) — combined
- Medical care services (~5%) — hospitals, doctors, professional services (note: most U.S. healthcare spending is in PCE, not CPI, because it's paid by employers and the government)
For each individual category page, see the detailed breakdowns linked above.
How BLS samples prices
Each month, BLS data collectors visit or call about 23,000 retail establishments and gather around 80,000 individual price observations. Outlets are chosen from the Telephone Point-of-Purchase Survey (TPOPS), a separate BLS survey that asks consumers where they actually shopped recently. This is why CPI captures real consumer experience — it follows the consumer to the store rather than imposing a fixed retailer list.
For items that consumers don't buy at retail — rent, OER, transportation services, medical services — BLS uses specialized surveys. Rent samples about 50,000 housing units on a six-month cycle. OER asks homeowners what they think their home would rent for, and is anchored using observed market rents from the same panel.
Geographic coverage is built from 75 urban areas grouped into four Census regions and four city-size classes. The published "U.S. City Average" is a weighted aggregate. BLS also publishes separate CPI data for 23 major metropolitan areas — useful if you want to know whether inflation is hitting New York differently than Houston.
Item-level prices feed up through a Laspeyres-type formula at the upper level and a geometric-mean formula at the lower level, the latter introduced in 1999 to correct a small upward bias in the older formula. The geometric mean approximates how consumers substitute toward cheaper varieties within narrowly defined item categories.
Frequently asked questions
How many categories are there in CPI?
The BLS organizes the consumer basket into eight major expenditure groups: housing, transportation, food and beverages, medical care, energy, education and communication, recreation, and apparel. Each is further divided into hundreds of item strata.
Which CPI category has the largest weight?
Housing, including shelter, household furnishings, and household operations, is by far the largest at roughly 45% of the basket. Within housing, shelter alone (rent and owners' equivalent rent) is around 35%.
How are CPI weights determined?
Weights come from the Consumer Expenditure Survey (CES), which tracks what urban households actually buy. Beginning in 2023, BLS updates weights annually with a one-year lag; previously the update was biennial.
Why are food and energy separated in core CPI?
Both categories are dominated by global commodity prices and weather, which swing month to month independently of underlying demand. Excluding them gives a clearer view of trend inflation.
Do CPI weights change year to year?
Yes, but typically only slightly. Annual reweighting captures shifts in spending — for example, more on services and less on goods over the past two decades.
Where can I see the official weights?
BLS publishes the Relative Importance tables annually at bls.gov/cpi. Each table shows the share of the index attributable to every category, sub-category, and item.