There are many ways one can calculate his or her BMR. The two methods shown below involve knowing your lean body mass (the first method) and your weight and height (the second method) Although the first method is more accurate, I prefer the second one for the simple fact that the values used to calculate BMR (Weight and Height) can be measured very accurately without any sophisticated instrument while the measure of the lean body mass can easily be erroneous unless it is performed with highly sophisticated systems. The video shown below shows a simplified way to calculate lean body mass, however this measure is mostly valuable to follow your progress but really not to detrmine your full lean body mass. The two methods to calculate BMR are: 1. Katch-McArdle formula to calculate BMR for men and women: BMR = 370 + (21.6 X lean body mass in kg) Example: If your lean body mass is 120 lbs, first we should convert to kilograms by dividing by 2.2. The answer is 54.54 or 55 Kg. BMR = 370 + (21.6 x 55) = 1548 Calories. That means, you need to consume 1548 calories to get enough calories if you would spend the whole day resting to maintain your current weight. 2. If you know your height and your weight, you can calculate your Basal Metabolic Rate (BMR) using the following equation:  Men: BMR = 66 + (13.7 X wt in kg) + (5 X ht in cm) - (6.8 X age in years) Women: BMR = 655 + (9.6 X wt in kg) + (1.8 X ht in cm) - (4.7 X age in years) NB. 1 inch = 2.54 cm.                  1 kilogram = 2.2 lbs.