How many carbs are in mushrooms?

While the amount of carbohydrates in mushrooms varies by type, white button mushrooms, a very common variety in the United States, contain approximately 1 gram of carbohydrates per 1/2 cup. A medium white button mushroom contains approximately 0.5 grams of carbohydrates.

Portabella mushrooms have a slightly higher carbohydrate count, at approximately 1.5 grams of carbohydrates per 1/2 cup. One large portabella cap contains 3 grams of carbohydrates. Mushrooms are often used in low-carb diets and can also serve as a substitute for meat in vegetarian or vegan diets. Some people also use mushrooms in a 50/50 blend with meat, such as hamburger, for flavor.