Plain popcorn calories come to 31 for one cup (8 g) of air-popped kernels and 387 per 100 g. Look at the distance between those two numbers. Popcorn is mostly air, so a full bowl weighs very little, and the low count holds only while you leave out the oil, butter and salt.
31kcal
1 cup · 8 g, air-popped, no butter
13%protein
1 gProtein
6 gCarbs
0.4 gFat
How to burn off 31 kcal
—Walking, brisk
—Jogging
—Cycling, moderate
—Swimming
Skip the math. BodyPal counts these calories from your steps and workouts automatically.
Nutrition facts
Air-popped, no butter · per 8 g
Calories
31 kcal
Protein
1 g
Carbohydrate
6.2 g
Fat
0.4 g
Saturated fat
0.1 g
Cholesterol
0 mg
Sodium
1 mg
Potassium
26 mg
Iron
0.3 mg
Source: USDA FoodData Central
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Verified nutrition data
Numbers on this page come from USDA FoodData Central, the U.S. Department of Agriculture’s food composition database, and from manufacturer labels where a branded product is named. Last verified September 2026. How we verify our data →
Plain popcorn: calories, protein and sodium by serving
Percent of daily value uses the FDA reference of 2,000 kcal a day.
Serving
kcal
Protein
Carbs
Fat
Sodium
% DV kcal
1 cup (8 g)
31
1 g
6.2 g
0.4 g
1 mg
2%
1 oz portion (28 g)
108
3.6 g
21.8 g
1.3 g
2 mg
5%
Single-serve bag (57 g)
275
5.8 g
34.9 g
13.3 g
351 mg
14%
100 g
387
12.9 g
77.8 g
4.5 g
8 mg
19%
3 × 1 cup (8 g)
93
3.1 g
2 mg
5 × 1 cup (8 g)
155
5.2 g
3 mg
Five cups of air-popped popcorn come to 155 calories
One cup weighs only 8 g and has 31 calories, which is 2% of the daily value. Because each cup weighs so little, the total climbs slowly. Two cups are 62 calories, three cups are 93, and five cups, a real bowl, come to 155 calories at just 40 g.
Weight is the more honest measure for big batches. A 1 oz portion (28 g) works out to 108 calories, 5% of the daily value, with 3.6 g of protein and 4.1 g of fiber. Read the bag carefully if it lists a serving by weight, because a few cups of plain popcorn and an ounce of it are the same food on two different scales.
Where it goes wrong is the cooking, not the portion. The per-100 g figure of 387 sounds high next to other snacks, but nobody eats 100 g of air-popped popcorn in one sitting by accident. That would be more than twelve level cups. For most people the bowl, not the scale, decides the total, so pick the bowl before you start eating.
Carbs supply 77% of the calories, and a lot of that is fiber
Popcorn is a whole grain, and its calorie split shows it: 77% from carbs, 13% from protein and 10% from fat. Per 100 g that is 77.8 g of carbohydrate, 12.9 g of protein and 4.5 g of fat, of which only 0.6 g is saturated.
The carb number needs context. Of those 77.8 g, 14.5 g is fiber and just 0.9 g is sugars. A single cup carries 1.2 g of fiber and 0.1 g of sugars, so this is a starchy, fibrous snack rather than a sweet one. That fiber, together with the volume, is why a bowl of plain popcorn feels like more food than its calorie count suggests.
Protein is a supporting player. At 12.9 g per 100 g it reaches 26% of the daily value, but one cup gives you only 1 g, or 2% of the daily value. Five cups bring 5.2 g. Popcorn will not carry a meal's protein on its own; treat it as a carb snack with a useful side of fiber.
A single-serve bag is a different snack
Air-popped popcorn barely registers on sodium: 1 mg per cup and 8 mg per 100 g, which rounds to 0% of the daily value. It also has 0 mg of cholesterol. Those rows change fast once popcorn is made in oil and salted for a bag.
The single-serve bag (57 g) in the servings table comes from a separate USDA entry for packaged popcorn, and the numbers show the difference. It has 275 calories, 14% of the daily value, with 13.3 g of fat and 351 mg of sodium, which is 15% of the daily sodium value in one small bag. Compare that with 1.3 g of fat in a 1 oz portion of air-popped popcorn.
If you watch sodium or fat, the label matters more than the word popcorn. A bag that says plain may still be oil-popped and salted. Air-popped at home, or a bag that lists only corn, keeps you close to the 31-calorie cup.
Plain popcorn works best as a volume snack
Plain popcorn earns its place when you want something to munch on for a while. Three cups at 93 calories take time to eat and fill a bowl, which suits an afternoon slump or a movie at home better than a dense snack of the same weight.
Because it is low in protein and fat, it pairs well with foods that cover those gaps. A piece of cheese, a handful of nuts or a glass of milk next to the bowl makes the snack more filling. Season with spices, a little grated cheese or a light mist of oil, and log what you add, because toppings can quickly outweigh the corn.
The simplest habit is to measure once. Pop a batch, weigh or count the cups, and you will know what your usual bowl costs. BodyPal can log the bowl from a photo, which helps on nights when you pour without measuring.
How does plain popcorn compare?
Here is how plain air-popped popcorn stacks up against popped, microwave and movie theater popcorn, per 100 g and per usual serving.
Verdict: For the lowest count, plain or popped popcorn wins at 387 calories per 100 g and 31 per cup, while microwave popcorn runs 535 per 100 g and 465 per bag. Movie theater popcorn is the one to share or skip, with 862 calories in a medium order, 48.7 g of fat per 100 g and 762 mg of sodium per 100 g.
Most popular plain popcorn brands in the United States
Ranked by popularity in the BodyPal database
# Productkcal / 100 g
1Whole Foods Market Plain Popcorn3.5 cup · 30 g467 kcal
Bagged plain popcorn is popped in oil, so label numbers run higher than the air-popped figures above. Source: manufacturer labels / USDA FoodData Central.
Plain popcorn FAQs
How many calories are in a cup of plain popcorn?
About 31 calories in one cup of air-popped plain popcorn (8 g). A 3-cup bowl comes to 93 calories.
Is plain popcorn good for weight loss?
Plain popcorn is 387 calories per 100 g, but a cup weighs only 8 g, so a 3-cup bowl is 93 calories with 3.5 g of fiber.
Plain popcorn vs microwave popcorn: which has fewer calories?
Air-popped plain popcorn is 387 calories per 100 g, while plain microwave popcorn is 518 because it pops in oil. Per cup that is 31 calories against 57.
How much protein and fiber are in plain popcorn?
100 g has 12.9 g protein and 14.5 g fiber. One cup (8 g) has 1 g protein, 1.2 g fiber and 6.2 g carbs.
How many calories are in 5 cups of plain popcorn?
Five cups of air-popped popcorn (40 g) have 155 calories. That bowl also gives 5.2 g of protein and just 3 mg of sodium, as long as you skip butter, oil and salt.
How many calories are in an ounce of plain popcorn?
A 1 oz portion (28 g) of plain popcorn has 108 calories, 5% of the daily value. It brings 3.6 g of protein, 4.1 g of fiber, 1.3 g of fat and 2 mg of sodium.
How much sodium is in plain popcorn?
Air-popped popcorn has 1 mg of sodium per cup and 8 mg per 100 g, about 0% of the daily value. A salted single-serve bag (57 g) jumps to 351 mg, or 15% of the daily value.
Does plain popcorn have sugar or cholesterol?
Plain popcorn has 0.9 g of sugars per 100 g and only 0.1 g per cup. It has 0 mg of cholesterol, and saturated fat is just 0.6 g per 100 g.
Is air-popped popcorn the same as popped popcorn in calories?
Yes. Both come to 387 calories per 100 g and 31 per cup (8 g), with the same 12.9 g of protein and 4.5 g of fat per 100 g. The difference starts when oil or butter is added.
