Published 2026-10-02
Fries Watch: the cheapest fries in the US cost $1.42 per 100 g, at Five Guys
Drive Thru Index weighed up the fries at 7 fast food brands across the US, using each brand's published serving weights and the median price at its restaurants on October 2, 2026.
Data as of .
Key facts
- Five Guys has the cheapest fries: $1.42 per 100 gLarge Cajun Fries, 572 g for a median $8.15.
- KFC is the most expensive: $3.14 per 100 gSecret Recipe Fries, 111 g for a median $3.49.
- Whataburger sits in the middle at $2.05 per 100 gOf 7 brands that publish their serving weights.
Fast food chains are collecting more and more data about their customers through mobile apps and loyalty programs: accounts with their details, and what they order and when. They are also experimenting with AI and data-driven pricing. Meanwhile the same item can cost very different amounts from one restaurant to the next, and customers cannot see why. Drive Thru Index publishes every restaurant's real price, every day, so anyone can check.
Per 100 g, the cheapest fries are Five Guys's Large Cajun Fries (572 g for a median $8.15, or $1.42 per 100 g). The most expensive are KFC's Secret Recipe Fries (111 g for $3.49, or $3.14 per 100 g).
Each brand's best value size, per 100 g: Five Guys $1.42, Burger King $1.63, Arby's $1.76, Whataburger $2.05, Taco Bell $2.13, McDonald's $2.64, KFC $3.14.
Anthony Gherghetta, an Australian software developer who built Drive Thru Index, started it after reading some of the buzz about AI being used to set fast food prices: he wanted to see whether it was true, and how big the price differences between restaurants really were. Prices bear out the contrast he noticed. In Australia, 97% of McDonald's restaurants charge within 10% of the typical Big Mac price; in the US, 53% do. The gap between the cheapest and the dearest tenth of restaurants is 10% of the typical price in Australia and 33% in the US.
“I kept reading that fast food chains were starting to use AI and customer data to set prices, so I wanted to see if it was true and how big the differences really were. In Australia, where I’m from, a Big Mac costs much the same wherever you buy it. In the US the price changes from one restaurant to the next. Fast food apps now know what you order, when and where, but customers can’t see how prices are set. So I built Drive Thru Index to check every restaurant, every day,” said Gherghetta.
Quotable lines
Per 100 g, Five Guys has the cheapest fries in the US ($1.42) and KFC the most expensive ($3.14).
Images
The facts behind the release
Every figure is from our prices of 2026-10-02, with the page on this site that shows it.
| Figure | Value | Where to see it |
|---|---|---|
| Five Guys has the cheapest fries: $1.42 per 100 g | Large Cajun Fries, 572 g for a median $8.15. | See the page |
| KFC is the most expensive: $3.14 per 100 g | Secret Recipe Fries, 111 g for a median $3.49. | See the page |
| Whataburger sits in the middle at $2.05 per 100 g | Of 7 brands that publish their serving weights. | See the page |
| Cheapest fries (restaurants): Five Guys | $1.42 | See the page |
| Most expensive fries (restaurants): KFC | $3.14 | See the page |
Methodology, about and contact
Fries Watch divides each size's median pickup price across a brand's restaurants on October 2, 2026 by the serving weight the brand publishes, and takes each brand's best value size. Only brands that publish weights are included. Prices are in US dollars and are not converted; only fries are compared between brands, never baskets.
About Drive Thru Index: Drive Thru Index (drivethruindex.com) publishes the menu price of every item at every restaurant of the biggest fast food brands, collected each day from the chains' own ordering apps. As pricing becomes more data-driven, it exists so that customers can see what each restaurant really charges and how it compares with others nearby. It covers the US, Canada, Australia, New Zealand, the UK, Ireland, Spain, Mexico and the Netherlands. Brands are only compared with themselves, and prices are never converted between currencies. Its figures are free to quote with attribution: "Source: Drive Thru Index".
The images with this release are free to use with the credit "Image: Drive Thru Index (drivethruindex.com)".
Media contact: anthony@drivethruindex.com
Background sources
Not part of the release: reporting that backs up its one line of context, for questions from journalists.
- How restaurant loyalty programs can drive more traffic and improve experiences Restaurant Dive, 2024-08-15
Restaurant loyalty apps pull in customers' ordering history and preferences, to personalise offers and recommendations (the intro's apps and loyalty programmes). - Wendy's backtracks on dynamic pricing Restaurant Dive, 2024-02-28
Wendy's told investors it would test dynamic and AI-enabled pricing on digital menu boards from 2025, then said after a backlash that it would not raise prices at the busiest times (the intro's experiments with data-driven pricing). - Inside McDonald's push to have AI price your Big Mac CNBC, 2026-09-29
Reports a Reuters investigation into an AI tool that recommends menu prices to McDonald's restaurants; McDonald's says franchisees remain free to set their own prices. Not quoted in the release text; the page could not be fetched to check its wording, only its search listing.