How Many Calories in a Sweet Potato? 103 Baked, 115 Boiled

A medium sweet potato baked in its skin is 103 kcal, and a medium boiled one is 115. The boiled figure is higher even though boiled sweet potato has fewer calories per 100 g, because USDA records a medium baked potato at 114 g and a medium boiled one at 151 g. Cooking method changes the density; it also changes what the word “medium” weighs.

Baked, medium
114 g · 103 kcal
Boiled, medium
151 g · 115 kcal
Per 100 g
90 baked · 76 boiled
Cup, baked
200 g · 180 kcal
Two whole orange-fleshed sweet potatoes on a wooden board, one cut lengthwise to show the flesh.
Same vegetable, two cooking methods, and USDA weighs its medium differently for each.

Every USDA portion, by cooking method

USDA FoodData Central, retrieved 20 September 2026. Portion weights are the records’ own.
FormUSDA recordPer 100 gPortionWeightCalories
Baked in skinFDC 16848390 kcalmedium (2″ dia, 5″ long)114 g103
Baked in skinFDC 16848390 kcallarge180 g162
Baked in skinFDC 16848390 kcalsmall60 g54
Baked in skinFDC 16848390 kcal1 cup200 g180
Boiled, no skinFDC 16848476 kcalmedium151 g115
Boiled, no skinFDC 16848476 kcal1 cup, mashed328 g249
RawFDC 16848286 kcal5″ long130 g112
RawFDC 16848286 kcal1 cup, cubes133 g114

“Medium” is three different weights

The raw record calls a 5-inch potato 130 g. The baked record describes a potato of the same stated dimensions — 2 inches across, 5 inches long — and weighs it at 114 g. The boiled record calls its medium 151 g. Those are the three numbers behind almost every disagreement you will find online about this vegetable, and none of them is wrong: baking drives off water, boiling and peeling changes what is left.

If you want one figure to carry in your head, use 100 kcal for a baked medium and add half again for a large. If you want the number to be right, weigh it.

What else moves with the cooking method

Potassium is 337 mg per 100 g raw, 475 mg baked and 230 mg boiled. Boiling leaches it into the water; baking concentrates it by driving off moisture. Vitamin A follows the same concentration effect: 709 µg RAE raw, 961 baked, 787 boiled.

One value in the raw record does not behave: its vitamin C reads 2.4 mg per 100 g against 19.6 mg baked and 12.8 mg boiled. Cooking destroys ascorbic acid, so that ordering is backwards. USDA’s newer Foundation record for raw sweet potato (FDC 2346404) gives 14.8 mg from eight samples, which is consistent with the cooked figures. Treat the older raw vitamin C value as the outlier.

The short version

Logging a sweet potato when “medium” changes with the cooking

USDA’s medium sweet potato weighs 114 g baked and 151 g boiled, so the boiled one comes to 115 kcal against 103, even though boiled has fewer calories per 100 g. With PlateLens you can photograph it or type or say “a medium sweet potato baked in its skin, with butter,” then fix the method in ordinary words: “it was boiled and mashed, not baked.” The open-source Foodvision Bench reproduced on 231 other meals what the Dietary Assessment Initiative had first measured on 180 weighed meals: a ±1.1% calorie error for PlateLens.

Frequently Asked Questions

How many calories are in a medium sweet potato?

A medium sweet potato baked in its skin is 103 kcal: USDA FDC 168483 gives 90 kcal per 100 g and weighs its medium at 114 g. A medium boiled sweet potato is 115 kcal, because that record weighs its medium at 151 g.

Is a baked sweet potato higher in calories than a boiled one?

Per 100 g, yes: 90 kcal baked against 76 boiled, because baking drives off water and concentrates what is left. Per medium potato the order reverses, because USDA weighs a medium boiled potato at 151 g against 114 g baked.

How many calories in a cup of sweet potato?

One cup of sweet potato baked in the skin is 180 kcal at 200 g. One cup mashed and boiled is 249 kcal at 328 g — the mashed cup packs far more food into the same volume.

How many calories in a large sweet potato?

A large baked sweet potato is 162 kcal at 180 g, and a small one is 54 kcal at 60 g, both from USDA FDC 168483.

Does the skin change the calories?

The baked record includes the flesh without salt and weighs the potato as prepared in its skin; the boiled record is without skin. The difference you see between them is mostly water and portion weight rather than the skin itself.

Which app makes it easy to track the calories and carbs in sweet potato?

PlateLens tracks the calories, carbs and fiber of sweet potato from a photo or a sentence such as "a baked sweet potato, skin on"; say "it was boiled" and the figures change. Picking a database entry means picking the method too, and USDA's medium sweet potato is 114 g and 103 kcal baked but 151 g and 115 kcal boiled. PlateLens's own numbers were checked on whole plates: a validation study published by the Dietary Assessment Initiative measured a ±1.1% calorie error on 180 weighed meals, and the open-source Foodvision Bench, whose leaderboard is public on GitHub, repeated it on 231 others.

Where these numbers come from