Is Sweet Potato Keto? Carbs per 100g, Portions and Swaps
Is sweet potato keto? Not in usual portions. UK food data lists boiled sweet potato at 13.0g of carbohydrate per 100g and baked sweet potato at 27.9g, so a 150g baked portion has about 42g, more than a strict 20g keto day. A weighed 50g of boiled sweet potato, about 6.5g, can fit on a day with room to spare. For chips and mash, celeriac, swede and cauliflower are the usual swaps.
At a glance
- 13.0gcarbs per 100g of boiled sweet potato (CoFID)
- 27.9gcarbs per 100g of baked sweet potato (CoFID)
- 6.5gcarbs in a 50g portion of boiled sweet potato
- 1.9gcarbs per 100g of boiled celeriac, a common swap
On this page
Sweet potato turns up as fries, mash, jackets and traybakes, so it's one of the vegetables people most often ask about when they start keto. This guide gives the carbs in sweet potato per 100g and per portion, cooked different ways, how it compares with ordinary potatoes and yams, and what to use instead.
Is sweet potato keto?
Not in usual portions. CoFID, the UK's official food composition dataset, lists sweet potato boiled without its skin at 13.0g of carbohydrate per 100g and baked sweet potato at 27.9g. The boiled figure comes from 11 samples of imported sweet potatoes analysed for Public Health England in 2017.
For scale, the British Dietetic Association (BDA) puts very low carb, or ketogenic, diets at 20–50g of carbohydrate a day. A 150g portion of baked sweet potato has about 42g, so on a strict 20g day it uses the whole allowance twice over. Even on a 50g day it leaves very little for anything else.
UK carbohydrate figures already leave out fibre. Under UK labelling law, carbohydrate means carbohydrate "which is metabolised by humans", and fibre is counted separately. So the CoFID figure is the one to count, and you don't subtract the fibre again. Our guide to net carbs on UK food labels explains more.
That doesn't mean a forkful breaks keto. It means sweet potato is a food to weigh rather than a side to pile on the plate.
Speak to your GP, diabetes nurse or a registered dietitian before you make big changes to your diet. This is especially important if you have diabetes and take insulin or other medicines that can cause hypos, or take SGLT2 inhibitors, as your medication may need to change. The same goes if you're pregnant, breastfeeding or have a history of eating disorders.
Carbs in sweet potato per 100g
These are the sweet potato entries in CoFID 2021, per 100g as eaten:
| Sweet potato, per 100g | Carbs | Sugars | Starch |
|---|---|---|---|
| Boiled, flesh only | 13.0g | 9.4g | 3.6g |
| Steamed | 20.4g | 8.4g | 12.0g |
| Raw, flesh only | 21.3g | 5.7g | 15.6g |
| Wedges, baked in rapeseed oil | 24.7g | 18.8g | 5.9g |
| Baked | 27.9g | 14.5g | 13.4g |
CoFID 2021, food codes 13-646, 13-671, 13-463, 13-647 and 13-672. Carbs are total carbohydrate, which in UK data doesn't include fibre.
The big gap between boiled and baked is mostly water. CoFID lists boiled sweet potato at 81.2g of water per 100g and baked at 65.6g, so 100g of baked sweet potato packs in more of the potato itself. The entries also come from different sources: the boiled figures and the wedges come from 2017 UK analysis, while the raw, steamed and baked figures come from older published data and calculation. So read the table as a guide, not as an exact recipe count.
How many carbs are in a sweet potato?
It depends on the size and how it's cooked. Here's what typical amounts add, worked out from the CoFID figures above:
| Portion, cooked weight | Carbs |
|---|---|
| 50g boiled sweet potato | 6.5g |
| 100g boiled sweet potato | 13.0g |
| 150g boiled sweet potato | 19.5g |
| 50g baked sweet potato | 14.0g |
| 150g baked sweet potato | 41.9g |
| 100g sweet potato wedges | 24.7g |
Our calculation from CoFID 2021 per 100g figures (13-646, 13-672, 13-647), rounded to one decimal place.
Sweet potatoes vary a lot in size, so weigh yours after cooking rather than guessing. On a strict 20g day, 50g of boiled sweet potato uses about a third of the allowance. A 150g baked portion uses more than two days' worth.
Net carbs in sweet potato: UK and US figures
Many keto apps and websites use US data, where carbohydrate is worked out "by difference" and includes fibre. To get net carbs from a US figure, you take the fibre off. Here are the US figures from USDA FoodData Central:
| Per 100g (USDA) | Total carbs | Fibre | Net carbs |
|---|---|---|---|
| Raw | 20.1g | 3.0g | 17.1g |
| Boiled, without skin | 17.7g | 2.5g | 15.2g |
| Baked in skin, flesh | 20.7g | 3.3g | 17.4g |
USDA FoodData Central, SR Legacy, FDC IDs 168482, 168484 and 168483. Net carbs is our calculation: total carbohydrate minus fibre.
The US and UK figures don't match. US boiled sweet potato works out at 15.2g of net carbs per 100g against 13.0g in CoFID, and US baked flesh at 17.4g against 27.9g. The two datasets come from different samples and methods, and they calculate carbohydrate differently. Whichever figure you use, sweet potato has far more carbs than the vegetables usually eaten on keto. In the UK, count the carbohydrate on the pack or the CoFID figure, and don't subtract fibre from it.
Sweet potato vs potato: which has more carbs?
Swapping potato for sweet potato doesn't make a meal keto. Here's how they compare in CoFID:
| Per 100g, as eaten | Carbs |
|---|---|
| Sweet potato, boiled | 13.0g |
| New potatoes, boiled in skins | 14.9g |
| Mashed potato with butter | 15.9g |
| Old potatoes, boiled | 17.5g |
| Baked potato, flesh only | 18.0g |
| Sweet potato wedges | 24.7g |
| Roast potatoes | 26.4g |
| Potato wedges, homemade | 26.5g |
| Sweet potato, baked | 27.9g |
CoFID 2021, food codes 13-646, 13-495, 13-553, 13-490, 13-620, 13-647, 13-534, 13-566 and 13-672.
Boiled, sweet potato has a little less carbohydrate per 100g than boiled potatoes. Baked, it has more than a baked potato. Either way, both sit at 13g or more per 100g, so they're in the same place on keto: weigh small portions, or swap them out.
Are yams keto?
No. CoFID lists yam separately from sweet potato, and it has even more carbohydrate: 28.2g per 100g raw, 29.3g boiled and 37.5g baked. The boiled figure comes from 8 samples of fresh imported yams analysed in 2017. A 100g portion of boiled yam uses more than a whole strict 20g day, so treat yam the same way as sweet potato and potato, and use the swaps below.
CoFID 2021, food codes 13-397, 13-655 and 13-398.
Keto swaps for sweet potato
These vegetables do the same jobs as sweet potato, in chips, mash, roasties and stews, for a fraction of the carbs:
| Boiled, per 100g | Carbs |
|---|---|
| Celeriac | 1.9g |
| Pumpkin | 1.9g |
| Turnip | 2.0g |
| Cauliflower | 3.5g |
| Butternut squash | 5.1g |
| Swede | 5.8g |
| Carrots, old | 6.0g |
| Sweet potato, for comparison | 13.0g |
CoFID 2021, food codes 13-585, 13-549, 13-391, 13-513, 13-643, 13-650, 13-497 and 13-646.
- Chips and wedges: cut celeriac or swede into chips, toss in olive oil with smoked paprika and salt, and roast at 200°C (180°C fan) until golden at the edges, turning once.
- Mash: cauliflower or celeriac mash with butter. A 150g serving of boiled celeriac has about 2.9g of carbs and the same weight of boiled cauliflower about 5.3g, against 19.5g for boiled sweet potato. Our keto cottage pie tops the filling with a cheesy cauliflower mash.
- Roasties: roast celeriac cubes, turnip or cauliflower florets in olive oil or butter.
- Stews and curries: celeriac holds its shape in long cooking. Our keto beef stew uses celeriac and mushrooms in place of potatoes.
- For the orange colour: butternut squash and pumpkin give a similar colour and sweetness. Boiled butternut squash is 5.1g per 100g, but CoFID lists baked butternut squash at 8.4g, so weigh it too.
Our guide to keto versions of British comfort food has more swaps for pies, roast dinners and fish and chips.
If you do eat sweet potato on keto
- Weigh it after cooking and use the figure that matches how you cooked it: 13.0g per 100g boiled or 27.9g baked.
- Keep it to a small side, such as 50g of boiled sweet potato (about 6.5g), on a day when the rest of your meals have very few carbs.
- Mix it into a half-and-half mash. 75g of boiled sweet potato mashed with 75g of boiled celeriac comes to about 11.2g of carbs for a 150g serving, against 19.5g for sweet potato alone.
- Count what you add. Honey, maple syrup and sweet glazes add carbs on top of the potato, and so can the coatings on frozen sweet potato fries. Check the nutrition panel on anything shop-bought.
Free delivery on orders over £30.
The loaf contains gluten (wheat), soy and sesame, so check the allergy information on the product page.
Key takeaways
- Sweet potato isn't keto in usual portions: 13.0g of carbs per 100g boiled and 27.9g baked in UK food data.
- Baked has the most per 100g because it has lost water, so weigh it after cooking.
- It isn't a keto swap for potato: both are 13g or more per 100g however you cook them.
- Use celeriac, swede, turnip or cauliflower for chips, mash and roasties.
- Don't subtract fibre from UK figures, which already leave it out.
Frequently asked questions
Is sweet potato keto?
Not in usual portions. UK food data lists boiled sweet potato at 13.0g of carbohydrate per 100g and baked sweet potato at 27.9g. A 150g baked portion has about 42g, more than a strict 20g keto day. A weighed 50g of boiled sweet potato, about 6.5g, can fit on a day with room to spare.
Are sweet potatoes low carb?
No. Sweet potato is a starchy root vegetable. CoFID, the UK's food composition dataset, lists it at 13.0g of carbohydrate per 100g boiled and 27.9g baked. For comparison, boiled celeriac is 1.9g, boiled cauliflower 3.5g and boiled swede 5.8g per 100g, which is why those are the usual keto swaps.
How many carbs are in a sweet potato?
It depends on the size and how it's cooked. UK food data gives 27.9g of carbohydrate per 100g of baked sweet potato, so a 150g portion is about 42g. The same 150g boiled is about 19.5g, because boiled flesh holds more water. Weigh it after cooking and use the figure for that cooking method.
Can you eat sweet potato on keto?
Only in small, weighed portions. On a strict 20g day, 50g of boiled sweet potato uses about 6.5g of carbohydrate, roughly a third of the day. A whole baked sweet potato can use all of it. Most people on keto use celeriac, swede or cauliflower for chips, mash and roasties instead.
Does sweet potato have more carbs than potato?
It depends how they're cooked. In UK food data, boiled sweet potato has 13.0g of carbohydrate per 100g against 17.5g for boiled old potatoes. Baked sweet potato has 27.9g against 18.0g for baked potato flesh. Neither fits keto in normal portions, so the swaps are the same for both.
Sources
- Public Health England / Food Standards Agency. Composition of Foods Integrated Dataset (CoFID) 2021: sheet 1.3 Proximates, food codes 13-463, 13-646, 13-671, 13-647, 13-672, 13-397, 13-655, 13-398, 13-495, 13-553, 13-490, 13-620, 13-534, 13-566, 13-585, 13-549, 13-391, 13-513, 13-643, 13-644, 13-650 and 13-497.
- US Department of Agriculture. FoodData Central, SR Legacy: sweet potato, raw, unprepared (168482); sweet potato, cooked, baked in skin, flesh, without salt (168483); sweet potato, cooked, boiled, without skin (168484).
- Retained Regulation (EU) No 1169/2011 on food information to consumers, via legislation.gov.uk: Annex I (definitions of carbohydrate and fibre).
- British Dietetic Association. Low carb diets food fact sheet (20–50g of carbohydrate a day on a very low carb, or ketogenic, diet).
- Groovy Keto. Low Carb Keto Bread product page: carbs per slice, slices per loaf and allergy information. Checked 11 November 2026.
- Groovy Keto recipes and guides: Keto cottage pie and Keto stew (ingredients). Checked 11 November 2026.
