Methodology & sources
The idea
The Economist's Big Mac Index uses one standardized product to compare purchasing power across countries. This site points the same lens at time: every price is expressed in nominal dollars of its own year, and then re-expressed in 2026 dollars, in Big Macs, and in minutes of work. Dollars are a moving target; a Big Mac is roughly the same thing in 1967 and 2026.
The formulas
- Today's dollars. price × CPI2026 ÷ CPIyear, using the CPI-U annual average.
- "Walk into {year} with today's paycheck." Your nominal income ÷ that year's price. Fun, and a bit unfair, because dollars were worth more then.
- "Someone earning your equivalent salary." Your income deflated by CPI to that year's dollars, ÷ that year's price. This is the real comparison: did the item cost a larger share of a similar paycheck?
- Minutes to earn. price ÷ hourly wage × 60, pre-tax.
- Hourly incomes are annualized at 2,080 hours (40 h × 52 weeks).
- Yearly growth is the compound annual rate between the two years.
Interpolation and the est. badge
Each series is stored as a sparse list of documented anchor years. Years between anchors are linearly interpolated and flagged as estimated, drawn dashed on charts and italic in tables. Years after the last anchor carry it forward. Years before the first anchor have no value: the Big Mac did not exist before 1967.
Rate-type series (postage, federal minimum wage) are recorded as the rate in effect for the majority of days in each year, so a change that took effect in July shows up the following year. Everything else is an annual average of monthly prices.
Big Mac prices from 2000 onward come from The Economist's published dataset. Before that only a handful of documented anchors exist (1967, 1968, 1972, 1978, 1980 and the first Big Mac index in 1986), so 1987-1999 and the 1970s are interpolated and are the least precise part of the index. Pre-1980 grocery anchors come from secondary compilations of BLS bulletins and are approximate. Coca-Cola is an outright estimate and is labelled low confidence.
Caveats
- All prices are U.S. national averages. A Big Mac in Manhattan and one in Mississippi differ by more than some decades of inflation.
- Product sizes drift: a "loaf" is priced per pound here to sidestep shrinkflation; Big Mac patties have held at 1.6 oz each.
- The federal minimum wage is a floor. Since 2014 most workers are covered by higher state or local minimums.
- The most recent year's CPI is a partial-year average until December data is published, and the Census releases household income with a one-year lag.
Refreshing the data
Datasets live in src/data/ as JSON. Running npm run data:refresh pulls the BLS series listed below from the public BLS API (no key required, or set BLS_API_KEY for higher limits), averages monthly values into annual figures, and rewrites the affected files while preserving hand-curated years. Review the diff, then commit.
Sources
Consumer Price Index
Annual averages. 1913-1979 hand-entered from the BLS historical table; 1980 onward is overwritten by `npm run data:refresh`. The latest year may be a partial-year average until December data is published.
Big Mac 1 sandwich
National average. Values before 2000 are documented anchors, not a continuous survey: 1987-1999 and other gap years are interpolated and flagged. Menu prices vary by 20% or more between regions and franchisees.
- 1967-1980 Press-reported national prices: 45¢ at the 1967 Uniontown debut, 49¢ nationwide in 1968, 65¢ in 1972, about 90¢ in 1978 and $1.20 in 1980
- 1986 The Economist, first Big Mac index (September 1986): US price $1.60
- 2000- The Economist Big Mac index open data (big-mac-raw-index.csv), US local_price; years with January and July surveys are averaged
Gasoline 1 gallon, regular · BLS APU000074714
U.S. city average, all formulations of regular unleaded. Annual mean of monthly prices.
Milk 1 gallon, whole · BLS APU0000709112
U.S. city average. The per-gallon BLS series begins in 1995; 1980-1994 doubles the half-gallon series, which runs slightly higher per gallon than gallon jugs.
Eggs 1 dozen, grade A large · BLS APU0000708111
Egg prices are volatile: avian-flu outbreaks in 2015, 2022 and 2025 produced sharp spikes that annual averages smooth over.
White Bread 1 lb loaf · BLS APU0000702111
U.S. city average per pound; a standard supermarket loaf is 20-24 oz, so multiply accordingly.
Ground Coffee 1 lb, 100% ground roast · BLS APU0000717311
Supermarket ground coffee, not café drinks.
Ground Beef 1 lb, 100% beef · BLS APU0000703112
The raw material of the Big Mac itself: two all-beef patties.
Movie Ticket 1 admission
Industry average across all showings, including discounted matinees and children's tickets, so an evening adult ticket in a big city runs well above this. NATO did not publish 1968-70, 1972-73 or 2020; those years are interpolated.
Postage Stamp 1 first-class letter (1 oz)
Rate in effect for the majority of days in each year (a rate that changed in July, as in 2022-2025, shows up the following year). Forever stamps, introduced in 2007, are valued at the current rate.
Coca-Cola 12 oz can, grocery
Low-confidence estimate. Soda pricing is dominated by promotions and pack sizes; vending and restaurant prices run 2-4x higher than the per-can grocery figure used here.
Federal Minimum Wage $ per hour
Federal rate for covered non-farm workers, taken as the rate in effect for the majority of days in each year (so the July 2009 increase to $7.25 appears from 2010). Many states set higher minimums, especially after 2014.
Average Hourly Earnings $ per hour · BLS CES0500000008
Production and nonsupervisory workers, about four fifths of private payrolls. Annual average of monthly values; refreshed by `npm run data:refresh`.
Median Household Income $ per year
Current (nominal) dollars, one value per year, as currently published (2013 uses the redesigned-questionnaire figure; 2020 is the pandemic nonresponse-adjusted revision). The Census Bureau publishes each year's figure the following September, so the most recent year or two are carried forward.