How Many Calories in a Slice of Pizza? The Honest Answer

Cheese pizza is 268 calories per 100g by USDA data, so a slice runs roughly 215 to 375 depending entirely on its size. Why no single slice number exists, how to estimate yours, and an FAQ.

There is no single answer to "how many calories in a slice of pizza," and any site that gives you one is guessing at your slice. What is measurable is the density: USDA puts cheese pizza with a regular crust at 268 calories per 100 grams, with 10.4g of protein and 12.3g of fat. From there the slice is arithmetic on its weight, and real slices range from about 215 calories for a modest 80-gram slice to 375 for a 140-gram one, before toppings. This guide gives you the density, the math to price your own slice, and the two variables that actually move the number.

Official USDA numbers

Measure	Calories	Protein	Carbs	Fat
Per 100g (cheese, regular crust)	268	10.4g	29.0g	12.3g
USDA's own 81g serving	217	8.4g	23.5g	9.9g

Slice sizes vary by pizzeria, so the useful table is by weight, computed from the verified density above:

Slice weight	Approximate calories
80g (small, thin)	215
100g (standard)	268
120g (large chain slice)	322
140g (big NY-style slice)	375

Those weights are the variable you supply; the 268-per-100g figure is the USDA measurement doing the work. If you have ever wondered why two "one slice" logs produce different scale outcomes, this table is why.

The two variables that decide your slice

Size, which dominates. A 14-inch pizza cut in 8 gives slices nearly double the weight of a 10-inch cut in 8. Same word, different food. When you cannot weigh it, compare it to your hand: a slice that overhangs your palm is a 120g-plus slice.

Toppings and crust, which stack on top. The USDA figure is plain cheese on a regular crust. Pepperoni, sausage, extra cheese, and stuffed or pan crusts each add meaningfully, and creamy or oily toppings add fastest, because fat carries 9 calories per gram. A loaded slice is not a rounding error above a cheese slice.

Pizza math in real meals

Two standard slices: about 536 calories, a legitimate lunch
Three big NY slices: about 1,125 calories, which is most of a day's deficit-adjusted budget in one sitting
Half a large cheese pizza (4 slices at 120g): about 1,288 calories
Two slices plus two beers: 536 plus 306 (official beer numbers) = about 840 calories, the classic Friday that never enters a log

None of those numbers say do not eat pizza. They say count the slices honestly, because pizza is the single most common food people eat past their own estimate, the pattern documented in Why Calorie Tracking Apps Are Inaccurate.

How I log pizza in Nouri

Pizza is the food that exposes lookup-based tracking: you will not find your pizzeria in a database, the slice size is not on any label, and by slice three nobody is doing arithmetic. So I log it the way I would describe it to a friend: "three slices of pepperoni, big ny-style" goes into Nouri as one sentence and comes back itemized, with the portion assumption visible so I can bump it with a recalculate if the slices were monsters. That is also the honest version of a pizza night: a rough logged number beats a blank evening every time. Nouri is iPhone (iOS only), and you can try it free.

FAQ

How many calories in a slice of pizza?

Roughly 215 to 375 for cheese, depending on slice weight, computed from USDA's 268 calories per 100g. A standard 100g slice is about 268.

How many calories in a slice of pepperoni pizza?

More than cheese: pepperoni adds fat and calories on top of the 268-per-100g cheese baseline. Treat cheese as the floor and log toppings explicitly.

How many calories in a whole pizza?

Multiply the slice weight by the count: eight 120g slices is about 2,576 calories for a large cheese pizza. Toppings and stuffed crust push it higher.

How many calories in two slices of pizza?

About 430 to 750 depending on size, with roughly 536 for two standard 100g slices.

Is pizza bad for weight loss?

No food is disqualifying; the day's total decides, as covered in Calorie Counting 101. Pizza is simply dense and easy to eat quickly, so it deserves an honest slice count.

How much protein is in pizza?

About 10.4g per 100g of cheese pizza, so a standard slice carries roughly 10g, mostly from the cheese.

Does thin crust have fewer calories?

Per slice, usually yes, because there is less dough by weight; that is a size effect rather than a magic one. The density table above still applies to whatever the slice weighs.

How many calories in a slice of Domino's or Pizza Hut pizza?

Chains publish their own official numbers per slice and size, and those beat any generic figure. Where a chain publishes, use the chain; the USDA density is for the pizzeria that publishes nothing.

How do I estimate slice size without a scale?

Use your hand as the ruler: palm-sized is around 100g, noticeably overhanging is 120 to 140g. Pick your description and use it consistently.

How many calories in pizza crust alone?

It is most of the carbohydrate load: 29g of carbs per 100g of the finished slice comes largely from the crust. Leaving crusts is a real, if inelegant, reduction.

Should I log leftover pizza the next day?

Yes, and it is the most-skipped pizza entry there is. Cold slices count exactly the same as hot ones, see Common Food Logging Mistakes.

Why do calorie apps disagree so much on pizza?

Because they are each assuming a different slice. Once you supply the weight or a consistent description, the disagreement mostly disappears.

Count the slices, describe the size, and log the night as one sentence in Nouri. If drinks came with it, the alcohol guide has those numbers too.

Sources

USDA FoodData Central, SR Legacy: Pizza, cheese topping, regular crust, frozen, cooked (FDC 170317), per-100g values and USDA's 81g serving, fdc.nal.usda.gov (checked September 26, 2026)
Slice-weight rows are arithmetic on the USDA per-100g figure; the weights are stated ranges for real slices, not USDA portion data