- Take your weight, e.g., 134 lbs.
- Take your height, e.g., 5’5″
- Plug these two numbers into a Body Mass Index (BMI) calculator.
BMI = % of your total body weight that is composed of fat.
- Write down your BMI, e.g., 22.3% (0.223).
- Multiply your BMI times your total weight (e.g., 0.223 x 134 = 29.88). 29.88 pounds of this person’s weight is fat.
- Take your weight (134 lbs.) and subtract your fat (29.88 lbs.). That equals your lean body mass. E.g., 134-29.88 = 104.12 lbs. of lean body mass.
- At a minimum you’ll need 0.5 grams of protein per pound of lean body mass. Multiply 0.5 times your lean body mass weight. In our example, that’s 0.5 x 104 = 52 grams per day. Note: Mark Sisson of “Primal Blueprint” recommends 0.7-1.0 gram of protein per pound of body weight.
Disclaimer: Everybody’s body composition is different so BMI done by online calculation using weight and height is a general measurement. An accurate BMI must be done using expensive water tank tests. However, for most people’s purposes this free method of BMI calculation is good enough.
- More information on BMI, the way it’s calculated, and its reliability (men vs. women, seniors, athletes, etc.).
- You could also use this link to calculate your body fat percentage more accurately.
- Check out this page for healthy body fat percentages.