Potato vs sweet potato: carbs, fiber and net carbs
Full comparison · Calories · Carbs
Per 3.5 oz (100 g), potato has 21.1 g of carbohydrate (18.9 g net) and sweet potato has 20.7 g (17.4 g net).
Net carbs = total carbohydrate minus fiber.
| Potato | Sweet potato | |
|---|---|---|
| Total carbohydrate, 100 g | 21.1 g | 20.7 g |
| Fiber, 100 g | 2.2 g | 3.3 g |
| Net carbs, 100 g | 18.9 g | 17.4 g |
| Total sugars, 100 g | 1.2 g | 6.5 g |
| Carbs per serving | 31.3 g in 1 serving (5.2 oz, 148 g) | 41.4 g in 1 cup (7.1 oz, 200 g) |
| Net carbs per serving | 28 g | 34.8 g |
Net carbs is total carbohydrate minus fiber; it is a common counting convention, not an FDA label term. Total sugars include natural and added sugar; USDA does not separate them for these foods.
What the numbers don't tell you
Most people ask whether sweet potato is the healthier swap. Calories and carbs are close, 93 against 90 calories per 3.5 oz (100 g) baked. The big difference is vitamin A, and it depends on color: in one trial 4.4 oz (125 g) of orange sweet potato supplied 1,031 mcg of vitamin A a day, while white-fleshed sweet potato, described as devoid of beta-carotene, was the control.
No study we hold compares the two on blood sugar. In 10 healthy adults, boiled sweet potato had a glycemic index of 41 to 50, baked 82 to 94. For potato, frying is the signal: in three US cohorts, each extra three servings of fries a week went with 20 percent more type 2 diabetes, and baked, boiled or mashed potato showed no link. Overweight adults eating potatoes five to seven times a week still lost weight on a calorie cut over 12 weeks.
Cook potatoes in their skin, which keeps 90 percent of the folate, but peel them for infants and toddlers, for whom EFSA found a health concern from potato's natural toxins. Keep fries occasional. With kidney disease, an ACE inhibitor or a potassium-sparing diuretic, both are high in potassium, 790 to 950 mg a serving here, and food alone can push blood potassium too high, so ask your doctor how much fits.
Chilling cooked potato is often sold as a way to blunt its carbs. In a trial in women with raised fasting glucose, potato baked and then chilled for five days lowered insulin at 15 and 30 minutes by about a quarter against hot boiled peeled potato. The area under the blood sugar curve did not differ at all.
Evidence behind this note
- Level B White-fleshed sweet potato has so little beta-carotene that researchers used it as the placebo against the orange kind. Same vegetable, same name, and the difference between a thousand units of vitamin A and none. van Jaarsveld et al., American Journal of Clinical Nutrition, 2005
- Level C In 10 healthy adults eating 10 Jamaican sweet potato cultivars, boiled sweet potato had a glycemic index of 41 to 50, while baked (82 to 94) and roasted (79 to 93) were high. Bahado-Singh PS, et al. J Nutr Metab. 2011
- Level C Three servings of chips a week tracked with a fifth more diabetes, and the same amount of boiled or baked potato tracked with nothing. BMJ, 2025
- Level B In a twelve week trial everyone ate five to seven servings of potato a week, and everyone still lost weight. Cutting calories did the work, and the potato did not get in the way. Randolph et al., Journal of the American College of Nutrition, 2014
- Level E The Nordic review written to set guidelines concluded the evidence on potatoes is very limited and that how you cook them is what matters. Food Nutr Res, 2024
- Level E Boil a potato in its skin and it keeps nine tenths of its folate. Peel it first and pour the water away, and a quarter of the folate goes down the sink. Bake it in the skin and the potassium stays put entirely. USDA Table of Nutrient Retention Factors, Release 6 (2007), Agricultural Research Service
- Level E Europe assessed the natural toxins in potato and found a health concern for babies and toddlers at ordinary intakes, and for adults only at the high end. Peeling removes a quarter to three quarters of them. EFSA, Glycoalkaloids in potatoes: public health risks assessed, 2020
- Level E According to NIH ODS, in people with chronic kidney disease or on ACE inhibitors or potassium-sparing diuretics, even dietary potassium below the adequate intake can cause hyperkalemia. NIH Office of Dietary Supplements, Potassium Fact Sheet for Health Professionals
- Level E A medium baked potato weighs 10 oz (285 grams) and a medium boiled one weighs 170. Same word, same vegetable, and nearly double the food on the plate. USDA FNDDS 2021-2023, FoodData Central
- Level C A medium sweet potato of 150 g carries about 4.5 g of dietary fiber, 3 g per 3.5 oz (100 g), by the USDA FNDDS food table. USDA FNDDS, food code 73401000, Sweet potato, NFS (fdc_id 2709697)
- Level B Baked-then-chilled potato cut the insulin response by about a quarter against boiled potato in women with raised fasting glucose, while the overall glucose curve did not move at all. Patterson et al., Nutrients, 2019
- Level B The chilled potato in that trial took five days to make. It was baked for ninety minutes, then held at 4 degrees for five full days, and the authors picked five days on purpose to build up as much resistant starch as they could. Patterson et al., Nutrients, 2019
- Level E According to NIH ODS, the most common effect of long-term high beta-carotene intake, as from eating lots of orange sweet potato, is carotenodermia, a harmless yellow-orange skin that reverses when intake drops. NIH Office of Dietary Supplements, Vitamin A and Carotenoids Fact Sheet for Health Professionals
Written from the studies and agency guidance we hold for both foods, reviewed by the Bioma editorial system. How we verify.
Keep exploring
Read more about these foods
- Potato or sweet potato: closer than their reputations
- Potato: chilling it, and the enzyme before surgery
- Sweet potato: the orange kind is the whole point
What the studies say
- Does sweet potato help with constipation? Untested in chronic constipation
- Is sweet potato good for weight loss? No trial has tested the food itself
- Is sweet potato good during pregnancy? It raises vitamin A, effects on the baby untested
Rankings and guides
- Carbohydrates: what it does and how much you need
- Fiber: what it does and how much you need
- Which foods are highest in dietary fiber?
- Which foods are highest in carbohydrate?
- Added sugar: what it does and what the evidence shows
- Potato: full nutrition facts
- Sweet potato: full nutrition facts
More comparisons
Where the numbers come from
- Potato: USDA FoodData Central, Potatoes, baked, flesh and skin, without salt, FDC ID 170093 · full profile · all forms of potato
- Sweet potato: USDA FoodData Central, Sweet potato, cooked, baked in skin, flesh, without salt, FDC ID 168483 · full profile · all forms of sweet potato
Each food is one USDA entry, chosen as it is usually eaten. Other cuts, brands and preparations differ; the links show them. % DV uses FDA Daily Values for adults. How we verify.