How much does a portobello mushroom weigh?

On average, a single portobello mushroom can weigh between 2 to 4 ounces (56 to 112 grams). However, the size and weight of portobello mushrooms can vary depending on the growing conditions, variety, and stage of maturity. Some portobello mushrooms can be even larger, weighing up to 6 ounces (170 grams) or more.