How do you calculate percentage from protein?

To calculate the percentage of protein in a food item, divide the amount of protein (in grams) by the total weight of the food item (in grams), then multiply the result by 100. The formula is: (grams of protein / total grams of food) × 100 = percentage of protein. For example, if a food item weighs 200 grams and contains 50 grams of protein, the calculation would be (50 / 200) × 100 = 25% protein.