Interested in finding out how many calories and nutrients are in the foods you eat?
Try our free calorie food counter.
Peak Aerobic Capacity Calculator
Peak aerobic capacity is a measure of cardiovascular fitness and health. It is considered one of the best measures of health and longevity.
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Body Mass Index Calculator
What is the body mass index (bmi)? How can I know if my bmi is within normal limits? Is there an easy way to calculate it?
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Physical Fitness Test
Physical fitness is an important indicator of good health and longevity. If you are wondering how fit (or unfit) you are, please take a few moments and take our physical fitness test. While is seems deceivingly simple, this test is based on solid research.
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Basal Metabolic Rate & Daily Energy Requirements Calculator
Find out how many calories your body burns to stay alive - i.e. your basal metabolic rate. In addition, by inputting your activity level, you can find out what your total daily energy expenditure is.
very intense daily exercise or sports & physical job or twice daily training
What Exactly is the Basal Metabolic Rate?
The basal metabolic rate (or bmr) is defined as the basal metabolism of an animal. BMR is the minimal rate of energy expenditure compatible with life. In other words, it is the minimum amount of energy (expressed in number of calories) our body needs to stay alive at rest.
How Did You Calculate My BMR and Daily Energy Requirements?
There are several ways of calculating these numbers. One of the best known formulas is the Harris-Benedict equation for estimating the resting energy expenditure or REE (which is the same thing as basal metabolic rate or BMR).
Although the Harris-Benedict equation has been used for a long time (almost 100 years, to be more precise, since Harris JA, Benedict FG. published their study "A Biometric Study of Basal Metabolism in Man." in 1919) by health professionals and nutritionists to estimate people's basal metabolic rate, new studies have shown that in overweight or obese persons, this equation is not accurate, as it tends to overestimate the resting energy expenditure in overweight or obese persons by at least 5 percent.
As almost two thirds of Americans are overweight, and the situation in the rest of the developed world is not much different, we decided to use another equation, called the Mifflin equation, published in the February 1990 issue of the American Journal of Clinical Nutrition, under the title A new predictive equation for resting energy expenditure in healthy individuals.
As far as measuring your daily energy requirements is concerned, we used a formula that factors in the so-called activity factor. This is essentially a number based on the level of physical activity you selected in the calculator above. We then multiply the BMR by this activity factor, and the result is your daily energy requirements.
While these formulas are widely used to predict the basal metabolic rate, please keep in mind they only provide an estimate, as there is significant variability in basal metabolic rates between similar individuals, and even in the same individual, bmr can vary from day to day.
For the basal metabolic rate estimation to be accurate, several assumptions must be true at the time of measurement:
absence of gross muscular activity - i.e. you MUST be resting, and your muscles MUST be relaxed
post-absorptive state - i.e. 12 hours or more after the last meal
thermal neutrality - i.e. ambient temperature variations should be minimal
emotional disturbance must be minimal, as studies have shown that emotional upset, particularly apprehension, may result in rises in BMR of from 15–40 percent
awake state, as sleep tends to depress BMR by approximately 10 percent
If you want to read more about BMR variability, J.V.G.A. Durnin from the University of Glasgow Glasgow, Scotland, has published a very interesting paper on this topic, entitled BASAL METABOLIC RATE IN MAN.
Basal Metaboic Rate Calculator on YouTube
This metabolic rate calculator has been featured on YouTube.com - see the video below.
