A sweet potato baked in its skin has about 90 calories per 100 grams, along with roughly 2 grams of protein, 21 grams of carbohydrate, and just 0.15 grams of fat, according to USDA FoodData Central. So a medium baked sweet potato lands at about 103 calories. The sweet potato itself is naturally low in calories and rich in fiber and vitamin A. What changes the number on your plate, more than anything else, is how you cook it and what you put on top.
The quick answer: calories in a sweet potato
A plain sweet potato, baked or boiled with nothing added, is a low-fat, carbohydrate-rich vegetable. Because it has almost no fat, the calories come mostly from starch and natural sugars, and the total tracks closely with size.
Here is how the macros break down for 100 grams of sweet potato baked in the skin:
- Calories: about 90 kcal
- Carbohydrate: about 21 g
- Protein: about 2 g
- Fat: about 0.15 g
- Fiber: about 3.3 g
- Sugars: about 6.5 g
That is a lot of food for around 100 calories, with useful fiber, potassium, vitamin C, and a very high dose of vitamin A from beta-carotene. The sweet potato earns a spot among low-calorie, filling foods precisely because you get a satisfying portion for very few calories, as long as you keep the toppings in check.
Calories by serving size
“One sweet potato” is not a fixed amount, so the calories swing with the size you bake. The table below applies the USDA per-100-gram value for sweet potato baked in the skin (90 calories) to common sizes.
| Serving | Calories | Carbs | Protein |
|---|---|---|---|
| 100 g | about 90 | 21 g | 2 g |
| Small (4 oz / 113 g) | about 102 | 23 g | 2.3 g |
| Medium (about 114 g) | about 103 | 24 g | 2.3 g |
| Large (about 180 g) | about 162 | 37 g | 3.6 g |
The takeaway: a large baked sweet potato carries well over half again the calories of a medium one, all before toppings. If you are tracking carefully, weighing the sweet potato beats eyeballing it, because “a sweet potato” can mean anywhere from about 100 to 160 calories. For more reference numbers like these, our Food and Calorie Guides hub keeps them in one place.
Calories by preparation method
The sweet potato stays low in calories on its own. The cooking method and the fat or sugar you add are what move the total. The table below shows roughly how that plays out per 100 grams.
| Preparation | What changes | Approx. calories (per 100 g) |
|---|---|---|
| Boiled, no skin, no salt | Nothing added (some loss to water) | about 76 |
| Raw | Nothing added | about 86 |
| Baked, in skin, no salt | Nothing added | about 90 |
| Candied (with butter and sugar) | Added butter and sugar | about 150 and up |
A few practical points fall out of this:
- Boiling comes in lowest. Boiling without the skin lands around 76 calories per 100 grams, a touch below baking, partly because some starch and water content shift during cooking.
- Baking concentrates it slightly. Baking in the skin drives off a little water, so the same gram of sweet potato reads a bit higher than boiled, at about 90 calories per 100 grams.
- Candying and frying are the big jumps. Brown sugar, butter, marshmallow, or a deep fryer can push a sweet potato well past 150 calories per 100 grams. The added fat and sugar, not the vegetable, are the variable.
The pattern here is the same one behind a lot of smart food swaps: keep the base food, change the cooking method, and the calories fall into place.
Sweet potato versus regular potato
People often assume the sweet potato is the dramatically lower-calorie choice. On calories, the two are close. A baked sweet potato has about 90 calories per 100 grams, just a touch under a white potato baked with the skin.
Here is the comparison per 100 grams, baked with the skin:
| Food | Calories | Carbs | Fiber | Standout nutrient |
|---|---|---|---|---|
| Baked sweet potato | about 90 | 21 g | 3.3 g | Vitamin A, fiber |
| Baked potato (skin) | about 93 | 21 g | 2.2 g | Potassium, vitamin C |
For the full white-potato breakdown by size and preparation, see our guide to the calories in a potato. The differences worth knowing:
- Sweet potatoes have more fiber and are extremely high in vitamin A from beta-carotene, well above a day’s worth in a single medium one.
- White potatoes have a bit more potassium and slightly more vitamin C.
- For calorie counting, they are nearly interchangeable. Choose based on taste and the rest of your plate, not a big calorie gap, because there is not one.
A sweet potato also pairs naturally with a starch swap discussion: if you are weighing it against a grain, our guide to the calories in rice covers how a similar carbohydrate side stacks up by portion.
How sweet potatoes fit weight loss and a calorie budget
A plain sweet potato is more friend than foe when you are watching calories. Three things work in its favor.
It is filling for its calories. Sweet potatoes have a low calorie density, plenty of water and fiber, and that combination helps you feel full on fewer calories. That makes a calorie deficit easier to hold. Pair one with a lean protein like chicken breast and you have a balanced, satisfying plate that is easy to keep within budget.
The toppings are the budget, not the sweet potato. A medium baked sweet potato is about 103 calories. A tablespoon of butter adds roughly 100, a spoon of brown sugar another 50 or so, and candied or marshmallow-topped versions climb from there. Logging the sweet potato and each topping separately keeps the math honest, and it shows exactly where the calories are coming from. A quick way to put a daily number around all of this is our calorie calculator, and if you want a structured target you can follow, you can get a free plan.
Cooking method sets the ceiling. Baked or boiled, a sweet potato stays modest. Candied or fried, it can more than double. Choosing the preparation is the single biggest lever you have.
A few simple ways to keep sweet potatoes working for your goals:
- Bake or boil instead of candying or frying when calories matter, and save the sugary versions for when they fit your budget.
- Go light on the high-fat, high-sugar toppings. Try cinnamon, a squeeze of lime, or a little Greek yogurt instead of butter and brown sugar.
- Eat the skin. It adds fiber and nutrients for almost no extra calories. A tracking app like CalcEat lets you log the sweet potato and the toppings separately so nothing slips through.
The bottom line
A sweet potato baked in its skin is about 90 calories per 100 grams, so a medium one is roughly 103 calories, naturally low in fat and rich in carbohydrate, fiber, and vitamin A. A white potato is almost identical on calories, with more potassium but far less vitamin A. The big swings come from preparation: boiling and baking keep sweet potatoes light, while candying, frying, and sugary toppings can multiply the calories several times over.
Keep it simple: bake or boil, eat the skin, go easy on the butter and brown sugar, and a sweet potato is a filling, nutrient-dense, budget-friendly food rather than one to avoid. Track the sweet potato and what you put on it, stay consistent, and the numbers will take care of themselves.
This article is general information, not medical or dietary advice for your specific situation.
