Track Your Nutrition with AI

Snap a photo, track macros, and crush your goals instantly.

Get the Free App
USDA Nutrition Facts (varies by size, 100g base)

Calories & Macros in Onion

A highly flavored bulb essential in many global cuisines. Whether your goal is keto, weight loss, or bodybuilding, here is the exact nutritional breakdown you need to hit your macronutrient goals.

💡 Serving Size Guide

A standard serving of 1 medium weighs approximately 110g.
That means one serving contains 44 calories, 1.2g of protein, and 10.2g of carbs.

40 Calories per 100g
1.1g Protein
9.3g Carbs
0.1g Fat

Onion Micronutrients (100g)

  • Dietary Fiber 1.7 g
  • Total Sugars 4.2 g
  • Net Carbs (Total Carbs - Fiber) 7.6 g

Frequently Asked Questions

Is Onion good for weight loss?

With 40 calories per 100g, Onion can absolutely be part of a healthy diet. Because it contains 1.7g of dietary fiber and 1.1g of protein, it helps regulate satiety. Weight loss ultimately depends on your overall daily caloric deficit (TDEE).

Can I eat Onion on a Keto Diet?

The ketogenic diet requires you to monitor your Net Carbs. A 100g serving of Onion has 7.6g of net carbs (9.3g total minus 1.7g fiber). This makes it highly compatible with low-carb and keto diets.

Does Onion have high protein?

Providing 1.1g of protein per 100g, Onion is lower in protein. You may want to pair it with higher-protein foods to hit your macro targets.

Tired of manual macro math?

Stop typing "Onion calories" into Google. CalorTracker's AI food scanner lets you simply snap a photo of your plate to calculate calories and macros automatically.

Download CalorTracker Free