Your BMR, or basal metabolic rate (metabolism), is the energy (measured in calories) expended by the body at rest to maintain normal bodily functions. This continual work makes up about 60-70% of the calories we use ("burn" or expend) and includes the beating of our heart, respiration, and the maintenance of body temperature. Your BMR is influenced by a number of factors, including age, weight, height, gender, environmental temperature, dieting, and exercise habits.
Because of the increased activity of cells undergoing division, the younger the person, the higher (faster) the metabolism. And the taller and heavier a person is, the faster their metabolism. Because of the greater percentage of lean muscle tissue in the male body, men generally have a 10-15% faster BMR than women. And when you go on restrictive, traditional diets, your BMR can drop by as much as 20%. People living in tropical or very cold environments generally have BMR's 5-20% higher than those living in more temperate climates. In general, depending on the intensity and duration, consistent exercise can also increase your BMR.
To estimate your BMR, click here .
Note: BMR calculators should only be used to provide a rough guideline on daily energy expended. Actual values cannot be attained using such calculators, and may be quite inaccurate depending on several factors such as geographic location, body-type, diet, body composition, supplementation and some genetic factors. Values which extend +/-15% above and below your calculated BMR may be a more accurate representation of your actual BMR range as daily fluctuations are constant and your BMR is rarely the same on a daily basis.