How many carbs are in a sweet potato?
One medium sweet potato has about 24g of carbohydrate and 20g of net carbs. Sweet potatoes have more fiber than white potatoes and a somewhat lower glycemic index.
Carbs by portion
| Portion | Total carbs | Fiber | Net carbs |
|---|---|---|---|
| 1 medium sweet potato, raw (114g) | 23.6g | 3.8g | 19.8g |
| 1 cup, mashed (100g) | 20.7g | 3.3g | 17.4g |
| 100 grams | 20.7g | 3.3g | 17.4g |
Net carbs
One medium sweet potato has about 20g of net carbs, which is total carbs (24g) minus fiber (4g). The fiber content is higher than a comparable white potato, which contributes to sweet potato's lower glycemic index. See the net carbs guide.
Glycemic index of a sweet potato
The glycemic index of a sweet potato is about 63. Sweet potatoes have a lower GI than white or russet potatoes, partly because of their higher fiber content and different starch composition. Boiling keeps the GI around 46; baking raises it closer to 94 because the heat breaks down more starch to sugar. Cooking method makes a substantial difference with sweet potato.
For diabetes
One medium sweet potato has 24g of carbs. Boiled, the GI is about 46 (low). Baked, it climbs close to 94 (very high). This cooking-method gap is larger for sweet potato than for almost any other vegetable. If you have diabetes and eat sweet potatoes, boil or steam rather than bake when blood sugar management is a priority. Pair with protein and fat regardless of cooking method. See the diabetes carb-counting guide.
Keto and low carb
One medium sweet potato has about 20g of net carbs. It does not fit strict keto. A small portion (quarter of a medium) at about 5g of net carbs may fit some moderate low-carb plans, but standard sweet potato at a full serving is too high for keto.
Good to know
The dramatic difference between boiled and baked sweet potato GI (46 vs 94) comes down to how heat breaks down starches. Dry oven heat converts more starch to sugar (amylase activity continues longer in a slow-heating oven). Boiling in water stops the heat more abruptly. Yams and sweet potatoes are often mislabeled in US grocery stores; true yams are much starchier and drier than sweet potatoes and have different nutritional values.
Full nutrition (per 100g)
- Calories: 90.0 kcal
- Carbohydrate: 20.71g
- Fiber: 3.3g
- Sugars: 6.48g
- Protein: 2.01g
- Fat: 0.15g
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Get the appFrequently asked questions
How many carbs are in a sweet potato?
One medium raw sweet potato (114g) has about 24g of carbohydrate. One cup of mashed sweet potato (100g) has about 21g of carbs.
Does a sweet potato have fewer carbs than a white potato?
A medium sweet potato (114g) has about 24g of carbs, while a medium white potato (213g) has about 37g. Size differs significantly, but sweet potato has fewer carbs per 100g (21g vs 17g) and more fiber.
Is sweet potato keto?
No. One medium sweet potato has about 20g of net carbs. Small portions may fit some low-carb plans, but not strict keto.
Is a baked sweet potato higher GI than boiled?
Yes, significantly. Boiled sweet potato has a GI around 46. Baked sweet potato has a GI close to 94. The cooking method makes a major practical difference for blood sugar.
Are sweet potatoes good for diabetics?
Boiled sweet potato has a low GI (46) and is a reasonable choice in a moderate portion. Baked sweet potato has a very high GI (94) and should be used more cautiously. Portion size and cooking method both matter.