March 14 is Pi Day when Americans usually look forward to relishing discounted circular foods, especially pizza and pie.
Pi is the Greek mathematical constant “π” or numeral 3.14159, which represents the ratio of the circumference of a circle to its diameter. It is the first three digits of this number that provide the name day of March 14.
The day therefore has nothing to do with cuisine. But since 1988, it has turned into an unofficial foodies’ holiday across the U.S.
2025 is no exception: restaurants are already extending Pi Day deals that include an extra $3.14 pizza with every purchase.
Pie deals in their part have turned the last three digits of the “π” sign, namely 159, into a $1.59 discount.
This interesting mathematical approach has come up through such venues as Coldspring Bakery in Minnesota and some Burger King[s], among others.
How Much do Pizza and Pie Normally Cost?
Customers owe much to the math crowd for making pies accessible way below their normal costs for just this one day.
The $3.14 deal particularly recalls the steep pie and pizza price averages that have dogged these foods down memory lane.
In 2017, for instance, Forbes put pizza as least costliest at 7.25 bucks (Alaska) and most expensive at 14 bucks (North Dakota).
A big cheese pie in 2017 meanwhile averaged between $7.25 and 15, with the franchise eateries being cheaper than artisan diners.
From 2020 onward, the average pie in the United States has been costing an extra dollar each passing year. From a maximum $16.74 in 2020 through $17.81 in 2021, most eateries were charging up to $23 for large pies in 2023.
The same scenario is typical of pizzas. While a sizeable $10.99 pizza was still available in 2022, by 2024 only a 10-inch pizza fit the $8-15 range.
Large pizzas typically oscillate between $15 and 30, with the last price typical of specialty types featuring price-pushing tomatoes.
By bringing buy-one-get-one-free pizza and pie offers, Pi Day therefore illustrates how math can also chip in! Statistical math also shows that fast food spending in the United States runs into billions, per the below data.
United States Fast Food Spending Statistics
According to the U.S. Department of Agriculture (USDA), Americans spend $2.6 trillion on food alone, as of 2023. A staggering 10% of this amount or $1,200 per person per year goes to fast food purchases, as of 2022.
One of the best-loved restaurant foods is pizza. Some 3 billion 10-inch or larger pizza pieces undergo consumption in the U.S., annually. In perspective, this is equal to $37 billion per year, in 2019 dollars. It also implies that on any passing day 13% of people in the States above the age of 2 are eating pizza.
Have fast food prices kept up with consumer appetite?
The Federal Reserve Bank shows that select fast foods have grown in price terms by 85 index points in four decades. In 1985, frozen dinners such as pizza, beef, pork and poultry pieces were priced at just 100 index points. By January 2025, however, the same foods had risen to 185.288 index points.
Which was the peak spending year on pizza deliveries in the United States?
The COVID-19 period saw at-home deliveries peak to unprecedented levels because people could not go to restaurants. Spending hit $19.8 billion in 2021, the highest to date. By 2023, restaurant pizza deliveries spending had ameliorated to $16.5 billion. These values are about half what people in the United States spend on pizza each year.