Your BMR (Basal Metabolic Rate) is the number of calories your body needs each day to perform basic functions. From the time you go to sleep one night until you go to sleep the next night, your body is consuming calories to fuel the body. Nearly 75 percent of the calories you eat each day are used by the body for this purpose.  A regular routine of cardiovascular exercise can increase your BMR, thereby improving both health and fitness.

If you've noticed that as you get older it becomes harder to eat whatever you want and stay slim, it is because your BMR decreases as you age. Likewise, depriving yourself of food in hopes of losing weight also decreases your BMR, as your body adjusts to how it burns fuel.

If you eat more calories than your body metabolism needs, you will gain weight. There are 3,500 calories in every pound of body fat. So, if you eat 500 calories more a day than your body needs, you will gain one pound every week.

Knowing your BMR can help you maintain your weight, because you will know approximately how many calories you need each day. Your BMR is influenced by many factors:
    Gender. Men have a greater muscle mass and a lower body fat percentage. This means they have a higher basal metabolic rate.
    Medications. Some drugs slow down the BMR dramatically.
    Genes. Some people are born with faster metabolisms, some with slower metabolisms; this genetic metabolic fact cannot be changed.
    Age. BMR reduces with age. After age 20, it drops about 2 per cent per decade.
    Exercise. Physical exercise influences body weight by burning calories, but it also helps raise your BMR by building extra lean tissue (lean tissue is more metabolically demanding than fat tissue), so you burn more calories even when sleeping.
    Weight. The more your weight, the higher your BMR; for example: the metabolic rate of obese women is 25 percent higher than the metabolic rate of thin women.
Body Surface Area -- The greater your body surface area factor, the higher your BMR, i.e., tall, thin people have higher BMRs.
    Body Fat Percentage. The lower your body fat percentage, the higher your BMR; the higher body fat percentage in the male body is one reason why men generally have a 10-15 percent higher BMR than women.
    Diet. Starvation, eating disorders or serious abrupt calorie-reduction can dramatically reduce BMR by up to 30 percent. Restrictive low-calorie weight loss diets may cause your BMR to drop by as much as 20 percent.
    Other Factors. Other factors include: body temperature and health, hormones, external temperature, and glands/glandular function

A regular routine of cardiovascular exercise can increase your BMR, improving your health and fitness when your body's ability to burn energy gradually slows down.

For a quick BMR estimate, please enter your body weight in the chart below. Calculations for the estimate are based on calories for basic body functions + calories for activity + calories for Specific Dynamic Effect (SDE) of food digestion. Results are based on the levels of daily activity specified.