How to Test Your RMR Metabolism at Home

Use a calculator to determine RMR when medical testing is not feasible.

Resting metabolic rate is the amount of energy that a person burns while resting, at a comfortable temperature and when the digestive system is inactive--usually 12 or more hours after a person's last full meal. RMR and the closely related basal metabolic rate are important measures for a person's health because these numbers provide a baseline metabolism for determining daily caloric needs to gain or lose weight. Although calculating BMR requires very precise measurements, anyone can calculate RMR at home with little difficulty.

Things You'll Need

• Calculator

Instructions

1. Determine your weight in kilograms. Multiply weight in pounds by 0.4536 to convert to kilograms.

2. Calculate your height in centimeters. Multiply height in inches by 2.54 to convert to centimeters.

3. Use the Mifflin equation to determine your RMR.

   For men, the equation is: (10 x w) + (6.25 x h) - (5 x a) + 5, where W = weight in kilograms, H = height in centimeters and A = age in years.

   For women, the equation is: (10 x w) + (6.25 x h) - (5 x a) - 161, where W = weight in kilograms, H = height in centimeters and A = age in years.

4. Multiply the result of the Mifflin equation by an activity factor to determine your actual daily resting metabolic rate, or the daily caloric intake you need at that activity level to maintain a constant weight. The activity factor is 1.2 for sedentary people (very little exercise), 1.375 for lightly active people (1-3 days of moderate exercise per week), 1.55 for moderately active people (3-5 days of moderate exercise per week), 1.725 for very active people (hard exercise 6-7 days per week) and 1.9 for extremely active people (hard exercise daily plus a physically intense job).

Tips & Warnings

• The Mifflin equation can be difficult to parse for people whose algebra is rusty. For example, a man who is 33 years old, stands 70 inches tall, weighs 205 pounds and engages in moderate exercise three days per week has an estimated RMR as follows: (10 x 92.99) + (6.25 x 177.8) - (5 x 33) + 5 x 1.55 = 2,916 calories.

• A person gains or loses 1 pound of body weight when she consumes or burns 3,500 more calories than her RMR. Therefore, if a person calculates her RMR to be 3,500 calories per day and she actually consumes 3,000, over the course of one week she will have a net calorie deficit of 3,500 (500 calories x 7 days), leading to the loss of 1 pound of weight.

• Home testing using mathematical models is not a substitute for proper testing by a physician or health professional. Do not set weight-reduction targets based on a home calculation of RMR without consulting with your physician.

References

• ShapeUp America: RMR Calculator
• Calories per Hour: Calculating BMR and RMR
• Medscape: Resting Metabolic Rate: A Critical, Primary Care Screening Test