Carbs in Yellow Onion

Keto-friendly

How many carbs are in yellow onion?

Yellow Onion has 6.7g net carbs per 100g — 8.6g total carbs minus 1.9g fiber — plus 0.8g protein, 0.1g fat, and 38 calories. That makes yellow onion relatively low in net carbs and lower than the typical vegetable, which averages about 17.9g net carbs per 100g. With this carb count, yellow onion fits a keto or low-carb diet (usually 20–50g net carbs per day) in normal portions. Values are per per 100 g, sourced from USDA FoodData Central; net carbs are computed by CarbMeNot.

Tracking yellow onion on keto?

Snap a photo and CarbMeNot logs the 6.7g net carbs in yellow onion — and everything else you eat — automatically. No database searching, no guessing.

Download on the App StoreGet it on Google Play
Free · no signup · ★ 4.7

Last updated June 10, 2026 · Reviewed by Jordan Lee, Nutrition Editor

Yellow Onion
6.7g
Net carbs
8.6g
Total carbs
1.9g
Fiber
0.8g
Protein
0.1g
Fat
38
Calories

Values per 100 g.

Is yellow onion keto-friendly?

Yes, in moderation

Yes, yellow onion can fit a keto diet in moderate portions. It has 6.7g net carbs per 100g (8.6g total carbs − 1.9g fiber). On a standard keto diet (20–50g net carbs per day), that leaves plenty of room for other vegetables and meals.

Carbs by serving size

ServingNet carbsTotal carbsCalories
100 g (3.5 oz)6.7g8.6g38
1 oz (28 g)1.9g2.4g11

How many calories are in yellow onion?

Yellow Onion has 38 calories per 100g. That's alongside 0.8g protein, 0.1g fat, and 6.7g net carbs per 100g.

Nutrition facts

NutrientAmount (per 100 g)
Calories38
Total carbs8.6g
Net carbs6.7g
Fiber1.9g
Sugar0g
Sugar alcohols0g
Protein0.8g
Fat0.1g
Sodium1mg
Potassium182mg

Source: USDA FoodData Central (Foundation). Net carbs = total carbs − fiber − sugar alcohols, computed by CarbMeNot.

Log yellow onion in one tap

Snap a photo and CarbMeNot's AI logs the carbs, protein, and fat automatically.

Download on the App StoreGet it on Google Play

Frequently asked questions

How many carbs are in yellow onion?
Yellow Onion has 8.6g of total carbs and 6.7g of net carbs per 100 grams.
How many net carbs are in yellow onion?
Yellow Onion has 6.7g of net carbs per 100 grams (total carbs 8.6g minus 1.9g fiber).
Is yellow onion keto-friendly?
Yes, yellow onion can fit a keto diet in moderate portions. It has 6.7g net carbs per 100g (8.6g total carbs − 1.9g fiber). On a standard keto diet (20–50g net carbs per day), that leaves plenty of room for other vegetables and meals.
How many calories are in yellow onion?
Yellow Onion has 38 calories per 100 grams.

Similar foods

CarbMeNot provides general nutrition information, not medical advice. Values are estimates — verify before relying on them for any health decision. See our Medical Disclaimer.