calculate protein needs by weight
Eating too much protein can also strain your kidneys and increase calcium loss. You can calculate your protein requirements based on your weight. Multiply your weight by 0.45 to convert to kilograms. For example, if you weigh 150 pounds, you weigh about 68 kilograms. Multiply your weight in kilograms by 0.8 to determine how many grams of protein you need per day. For example, if you weigh 68 kilograms, you need about 54 grams of protein per day. Weight lifters need up to 1.8 grams per kilogram per day, while endurance athletes require up to 1.4 grams of protein per kilogram of body weight, notes the Iowa State University Extension.