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Browsing Tag: BMR

Mifflin-St.Jeor Equation

Did you know, that for a 154lb man these are the approximate calories needed to live

calories for life BMR

I say approximate because there are many factors affecting RMR which is sometimes used interchangeably with BMR.

BMR = Basal Metabolic Rate taken after 8 hours of sleep, 12 hours of fasting and in a reclined position.

RMR = Resting Metabolic Rate that doesn’t require subject to spend the night sleeping.

Both are measured using the Mifflin-St.Jeor equation which is


The weight is in kilograms, the height is in centimeters and the age is in years.

An easy way to calculate kilograms is to take your weight in pounds and divide by 2.2 to get kilograms.

pounds to inches

To get your height in centimeters take the feet and multiple by 12 and add your inches to it and multiply by 2.54 to get centimeters.

feetandinches to cm

Then to figure out total daily calorie needs the BMR is multiplied by activity factor. AHA, that’s where the approximations come in. This activity factor is very important and you don’t want to over or under estimate because there will be a difference in calories.

You will find many sources have different numbers, so the equations are more of estimates rather than exact. This is why there is equipment to determine BMR such as the Douglas Bag and Body Gem.

But for the sake of estimation, we will use these numbers for energy expenditure

  • 1.200 = sedentary (little or no exercise)
  • 1.375 = lightly active (light exercise/sports 1-3 days/week, approx. 590 Cal/day)
  • 1.550 = moderately active (moderate exercise/sports 3-5 days/week, approx. 870 Cal/day)
  • 1.725 = very active (hard exercise/sports 6-7 days a week, approx. 1150 Cal/day)
  • 1.900 = extra active (very hard exercise/sports and physical job, approx. 1580 Cal/day)


So I’ll do mine.

  • Female = (10 * 50.9) + (6.25 * 162.56) – (5 *21years) – 161
  • 509 + 1016 – 105 – 161 = 1259
  • 1259 * activity level
  • 1259 *1.550 = 1951.45

So there you have it. That equation will help determine an ESTIMATED calorie requirement for you.