How To Calculate Your BMR and Calorie Needs

1. Estimate your BMR by using the following formula:

  • 370 + (9.8 x lean body mass in lbs) + BMR
  • To calculate your lean body mass, you need to have your body fat percentage.  You can do some research online to guestimate your body fat percentage, or you can ask your trainer, or get it done at a place that uses bod pod technology, or electrodes.  This is the most accurate you’re going to get.  After you have determined your body fat percentage, minus that percentage off your body weight… For example: if you weigh 150 lbs and you think you are around 20 percent body fat, your lean body mass would be 120 lbs (150-20%)
  • Enter it (lean body mass in lbs) into the formula, and voila, there is your BMR!
    Your BMR number is how many calories you would burn at rest if you rested for 24 hours straight.  Of course, that’s not the case, so now we have to factor in your activity level:

2. Activity Factor

  • Sedentary(desk job, not much exercise): BMR x 1.2
  • Moderate(Job on your feet or exercise 3 days per week): BMR x 1.375
  • Active(Heavy lifting job or exercise 5-6 times per week) : BMR x 1.55

Here is the number you have now found is how many calories you need to maintain your weight

3. Do you want to build muscle or burn fat?

  • If you want to gain weight, add 15-20% more calories
  • If you want to lose weight, subtract 15-20% of your calories


Pick one, work with it for awhile, then switch it up.  However, try not to drastically change your calories one day… try and progressively take them away or add them. Your body may go into a bit of shock if you go from eating 2000 calories to 1500…HUNGER PAINS ENGAGE.