How Many Calories in a Sweet Potato

A medium sweet potato (about 130–150 grams) contains roughly 110 to 130 calories, depending on size and preparation. That breaks down to around 86 calories per 100 grams for raw, skin-on sweet potato. Most of these calories come from complex carbohydrates, with a small amount of protein and very little fat. Despite being slightly higher in natural sugar than white potatoes, sweet potatoes are still a relatively low-calorie, nutrient-dense food, especially when baked or boiled without added fats.

Calories by Size and Weight

The calorie count of a sweet potato scales directly with size. A small sweet potato (about 100 grams) has roughly 86 calories. A medium-sized one weighs around 150 grams and contains about 130 calories, while a large sweet potato can reach 180 to 200 calories or more. Cooking methods can shift these numbers slightly due to moisture loss, especially when roasting or baking.

Calories by Cooking Method

How you cook a sweet potato can affect the final calorie content, not because the potato changes, but because of what’s added during prep. A boiled or steamed sweet potato retains the base calorie count, so a 150-gram serving still holds around 130 calories. A baked sweet potato, due to some water evaporation, may be slightly more calorie-dense per bite. Frying or roasting with oil adds calories fast, a single tablespoon of olive oil adds 120 calories, which can more than double the calorie count of the dish if used liberally.

Nutritional Breakdown of a Sweet Potato

Sweet potatoes are rich in complex carbs, with about 20 grams of carbs per 100 grams, including 3 to 4 grams of fibre and 5 to 9 grams of natural sugars, depending on variety. A medium sweet potato offers about 2 grams of protein, zero fat, and a wide array of micronutrients. They’re especially high in vitamin A (as beta-carotene) often providing over 300% of the daily requirement and also supply vitamin C, potassium, manganese, and antioxidants.

Health Benefits of Sweet Potatoes

Sweet potatoes are considered a high-volume, high-nutrient, moderate-calorie food, which makes them ideal for most eating plans. Their rich beta-carotene content supports immune function and eye health. The fibre supports digestion and helps regulate blood sugar when eaten with the skin. Sweet potatoes are naturally gluten-free and lower on the glycemic index than many refined carbs, making them a good alternative to bread, pasta, or rice, especially when prepared simply.

Downsides of Sweet Potatoes

While sweet potatoes are healthy, they can become calorie-dense quickly when topped with butter, marshmallows, brown sugar, or creamy sauces, especially around the holidays. Sweet potato fries are another trap: despite the vegetable’s health halo, frying adds a massive amount of calories, fat, and sodium. Portion size also matters. Because sweet potatoes are naturally sweet and satisfying, they can be easy to overeat when roasted in oil or mashed with rich ingredients.

Glycemic Index and Blood Sugar

Sweet potatoes have a moderate glycemic index, typically ranging from 44 to 63, depending on how they’re cooked. Boiling results in the lowest GI, while baking and roasting are slightly higher. Their fibre and slower-digesting starches make them more blood sugar–friendly than white potatoes or refined grains, especially when eaten with protein and fats that slow digestion further. This makes sweet potatoes a smart carb for people managing blood sugar or energy crashes.

How Sweet Potatoes Fit Into Your Diet

Sweet potatoes work in almost any eating plan, from fat loss to muscle gain. Their moderate calorie load, high fibre, and rich nutrient profile make them an ideal staple carb for meals. They pair well with lean proteins like chicken, fish, and eggs, or can be used in plant-based diets alongside beans, lentils, or tofu. For weight loss, sticking to baked or boiled versions with minimal added fat keeps the calorie count low while maximizing fullness. For energy needs, roasted sweet potatoes with olive oil or avocado offer a more calorie-dense, satisfying option.

What’s Actually in a Sweet Potato?

A plain sweet potato has one ingredient, sweet potato. There’s no fat, no added sugar, and no sodium unless you add it. This makes it a whole food with high nutrient density and clean, predictable calories. Packaged versions like sweet potato fries, chips, or frozen wedges usually include oil, salt, starches, or preservatives that can significantly raise the calorie content and reduce the health benefits. For best results, stick with fresh, whole sweet potatoes and control the seasonings yourself.

A Healthier Alternative?

Sweet potatoes are already one of the healthiest starches available, but if you're watching calories or carbs closely, cauliflower mash or roasted pumpkin can offer a lower-calorie, lower-carb alternative. That said, the nutritional trade-off isn’t always worth it. For most people, a small to medium sweet potato, baked, steamed, or boiled offers more satisfaction and nutrients per bite than most processed carb substitutes.

Cooking Water Loss Affects Calorie Density

When you bake or roast a sweet potato, it loses water, becoming more calorie-dense per bite. The calorie count doesn’t increase overall but because the weight goes down while the calories stay the same, each spoonful delivers more energy than the same spoonful of boiled or steamed sweet potato. That’s why roasted chunks feel heartier and more filling but can be easier to overeat. If you're tracking closely, using grams or weighing your cooked portion can help ensure accuracy.

Sweet Potatoes in Smoothies or Purees

Blended sweet potatoes used in smoothies, pancakes, or baby food are still roughly the same calorie count per 100 grams, but they digest faster and spike blood sugar more due to the broken-down fibre and starch. They also take up less physical space in your stomach, which may reduce satiety. If you're adding sweet potato to a smoothie for nutrition or texture, portion control becomes especially important. It’s easy to blend in 150+ calories worth without realizing it.

Sweet Potato Skins: Keep or Peel?

Eating the skin of a sweet potato adds a small amount of fibre and micronutrients, especially potassium and antioxidants. The calorie difference is minimal usually less than 10 calories per medium potato but the fibre makes it slightly more filling. If the potato is well-scrubbed and roasted, keeping the skin on is usually the better choice for both digestion and appetite regulation.

Candied or Holiday Sweet Potatoes: A Calorie Bomb

During the holidays, sweet potatoes are often prepared with butter, cream, brown sugar, and marshmallows, which transforms a 130-calorie food into a 300–400 calorie side dish. One serving of sweet potato casserole can easily hit 350 to 450 calories, depending on the ingredients. These versions are drastically different nutritionally than a plain baked sweet potato and shouldn’t be treated the same in meal planning or tracking.

Sweet Potatoes vs White Potatoes: The Truth

While sweet potatoes are often thought to be the “healthier” option, they’re not dramatically lower in calories than white potatoes. A boiled white potato contains about 77 calories per 100 grams, compared to 86 in a sweet potato. The real difference lies in the micronutrients as sweet potatoes are higher in vitamin A and natural sugars, while white potatoes offer more potassium and slightly more protein. Calorically, they’re nearly equal, it’s the preparation and toppings that typically make one option better for your goals than the other.

When Sweet Potatoes Help vs Hurt Your Diet

Sweet potatoes help your diet when they replace more processed carbs like white bread, sugary cereals, or fried starches. They hurt your diet when served in oversized portions, doused in butter or oil, or treated like a dessert. For fat loss or blood sugar stability, aim to keep sweet potato servings to half a medium potato to one whole medium, especially if paired with a lean protein and non-starchy vegetables.

Smart Carb Swap Cheat Ideas

Smart carb swaps are all about trading high-calorie, low-nutrient starches for options that are more filling, more nutrient-dense, or lower in calories per bite. Instead of white rice, try cauliflower rice or half-and-half blends that cut carbs without sacrificing volume. Swap regular pasta for spiralized sweet potato, zucchini noodles, or lentil-based pasta that packs in protein and fibre. Replace sandwich bread with whole grain wraps or lettuce leaves to reduce calorie load while still holding your meal together. Mashed potatoes can be lightened up by blending them with steamed cauliflower, and instead of chips or crackers, use roasted sweet potato slices, cucumbers, or bell pepper strips for dipping. These swaps don’t mean sacrificing satisfaction, they just make your meals work harder for your goals, helping you stay fuller longer with fewer hidden calories.

Summary

A medium sweet potato contains about 110 to 130 calories, with most of that coming from complex carbohydrates and fibre. Sweet potatoes are rich in vitamin A, potassium, and antioxidants, and when prepared simply, they’re a low-calorie, high-nutrient food that supports energy and satiety. As long as toppings and oils are controlled, sweet potatoes fit beautifully into any balanced diet from weight loss to performance eating.