Onions: net and total carbs, raw, cooked and dried
Published: 25 October 2026 · Updated: 25 October 2026 · Easy Keto. This page was written with the help of AI and published by Easy Keto. The nutrition values and the portion sizes in grams come from USDA FoodData Central; sources and calculation are below.
How many carbs are in onions?
Raw onions have 7.6 g net carbs per 100 g: 9.3 g total carbs minus 1.7 g fibre; boiled onions: 8.8 g net carbs (USDA FoodData Central). A medium onion (110 g) has 8.4 g net carbs.
The table gives USDA values for raw onions, onions boiled in water without salt and drained, frozen chopped onions before cooking and dehydrated onion flakes. USDA's raw row names no variety; spring onions are a separate food and not on this page.
The key points
- Onions, raw: 9.3 g total carbs per 100 g, of which 1.7 g fibre and 4.2 g sugars; 7.6 g net carbs; 0 g fat, 1.1 g protein, 40 kcal.
- Across the 4 rows of the table, net carbs range from 5.0 g to 74 g per 100 g.
- Net carbs = total carbs minus fibre. UK and EU food labels leave fibre out of carbohydrate, so compare the net carbs here, not the total carbs, with the carbohydrate on a UK label.
Nutrition per 100 g
| Food | Total carbs | Fibre | Net carbs | Sugars | Fat | Protein | kcal | FDC ID |
|---|---|---|---|---|---|---|---|---|
| Onions, raw | 9.3 g | 1.7 g | 7.6 g | 4.2 g | 0 g | 1.1 g | 40 | 170000 |
| Onions, boiled | 10 g | 1.4 g | 8.8 g | 4.7 g | 0 g | 1.4 g | 44 | 170001 |
| Onions, frozen, chopped, uncooked | 6.8 g | 1.8 g | 5.0 g | – | 0 g | 0.8 g | 29 | 170410 |
| Onion flakes, dried | 83 g | 9.2 g | 74 g | 37 g | 0 g | 9.0 g | 349 | 170002 |
Net carbs = total carbs minus fibre, calculated from the unrounded USDA values and rounded afterwards. USDA counts fibre as part of total carbs; UK and EU labels leave it out of carbohydrate, so the net carbs here correspond to the carbohydrate on a UK label (USDA calls this “available carbohydrate”). Our recipes count net carbs as that carbohydrate minus erythritol; USDA lists no erythritol for these foods, so nothing else is subtracted (how we calculate net carbs).
Source: U.S. Department of Agriculture, FoodData Central, SR Legacy (April 2018), public domain (CC0 1.0), retrieved on 21 October 2026. Values per 100 g of the edible part as published, rounded like the nutrition tables on our recipe pages: kcal to whole numbers, grams from 10 g to whole grams, below that to 0.1 g, up to 0.5 g shown as “0 g” (How we calculate nutrition values). So “0 g” means at most 0.5 g. “–” means that USDA gives no value; a missing value is not the same as 0 g. The table uses everyday names; USDA calls the rows: “Onions, raw” (FDC ID 170000), “Onions, cooked, boiled, drained, without salt” (FDC ID 170001), “Onions, frozen, chopped, unprepared” (FDC ID 170410), “Onions, dehydrated flakes” (FDC ID 170002). The values apply to the food as USDA describes it; they vary with variety, ripeness, origin and preparation. For packaged food, the nutrition label on the pack applies. These values are for guidance only; do not use them to calculate medication doses.
Carbs per portion
Onions, raw: 50 g has 3.8 g net carbs, 100 g has 7.6 g, 110 g (about 1 medium onion) has 8.4 g and 150 g (about 1 large onion) has 11 g. Calculated from the unrounded USDA values per 100 g and rounded afterwards.
| Amount | Total carbs | Net carbs | kcal |
|---|---|---|---|
| 50 g | 4.7 g | 3.8 g | 20 |
| 100 g | 9.3 g | 7.6 g | 40 |
| 110 g (about 1 medium onion) | 10 g | 8.4 g | 44 |
| 150 g (about 1 large onion) | 14 g | 11 g | 60 |
Portion sizes: USDA FoodData Central, FDC ID 170000, portions “1 medium (2-1/2" dia)” = 110 g and “1 large” = 150 g. Real portions vary, so the Amount column always gives the grams.
Related foods
Other foods from the group “Vegetables”:
Where the values come from
The values come from USDA FoodData Central, the food composition database of the U.S. Department of Agriculture, dataset SR Legacy (April 2018), the final release of its Standard Reference database, retrieved on 21 October 2026. USDA calculates carbohydrate by difference: 100 g minus water, protein, fat and ash. This value includes fibre; we show it as total carbs and subtract the fibre to get net carbs. Our recipes convert US values the same way, but they calculate vegetables and fruit with values from the German database BLS (see where the values come from), so a recipe can count different carbs for the same amount. USDA calculates protein as nitrogen × 6.25 for every row here, the same factor UK and EU labels use. The kcal values are USDA's own; UK and EU labels calculate kcal with fixed factors, so a label can show a different value. The row names in the table are everyday names; the full USDA description with its FDC ID is below the table. How Easy Keto calculates and rounds is explained on How we calculate nutrition values. This page shows values from a database and does not rate any food.
The German version of this page, Zwiebeln: Kohlenhydrate pro 100 g, roh und gekocht, shows different values. It uses the German nutrient database (Bundeslebensmittelschlüssel, BLS), which is based on other samples and sources and adds up sugars, starch, oligosaccharides and sugar alcohols to get carbohydrate without fibre; USDA calculates carbohydrate by difference, fibre included. So the net carbs here and the carbohydrate values on the German page differ.
See also
Recipes with onions from the Easy Keto app:
- Crustless Spinach Quiche (with 30 g onion)
Method and more:
- Browse and search all recipes in the app (free)
- Scale recipes from 1 to 10 servings (free)
Sources
- U.S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center: FoodData Central, SR Legacy (April 2018): FDC ID 170000 “Onions, raw”, FDC ID 170001 “Onions, cooked, boiled, drained, without salt”, FDC ID 170410 “Onions, frozen, chopped, unprepared”, FDC ID 170002 “Onions, dehydrated flakes”. Portions of FDC ID 170000: “1 medium (2-1/2" dia)” = 110 g and “1 large” = 150 g. Public domain (CC0 1.0), retrieved on 21 October 2026 through the FoodData Central API. USDA fields: “Carbohydrate, by difference”, “Fiber, total dietary”, “Total Sugars”, “Total lipid (fat)”, “Protein” and the kcal value. Values per 100 g used as published, converted to the portions and rounded.
- U.S. Department of Agriculture, Agricultural Research Service, Nutrient Data Laboratory: USDA National Nutrient Database for Standard Reference, Release 28, Documentation and User Guide (September 2015, slightly revised May 2016), pp. 13–14 (carbohydrate by difference, fibre, sugars, kcal), and USDA National Nutrient Database for Standard Reference, Legacy (2018), Documentation and User Guide (April 2018, slightly revised July 2018): Release 28 (PDF), Legacy (PDF), both retrieved on 21 October 2026.
- Regulation (EU) No 1169/2011 on the provision of food information to consumers, Annex I No. 7 (carbohydrate), No. 10 (protein) and No. 12 (fibre), Annex XIV (conversion factors for kcal): UK version on legislation.gov.uk (Annex I, Annex XIV), retrieved on 21 October 2026; EU version on EUR-Lex (consolidated text of 1 April 2025).
- Max Rubner-Institut (2025): Bundeslebensmittelschlüssel (BLS), Version 4.0 – Deutsche Nährstoffdatenbank (German nutrient database). Karlsruhe. DOI 10.25826/Data20251217-134202-0, licence CC BY 4.0, retrieved on 12 October 2026: description of the component “CHO” (carbohydrate, available = sugars + starch + oligosaccharides + sugar alcohols). Used here only to explain why the German version shows different values.
- How we calculate and round: How we calculate nutrition values (Easy Keto).