MetaCalc

My-Diet-Program.com - Metabolic Rate Calculator
Use this program to estimate your metabolic rate and the recommended calorie intake according to your height, weight and age. Also taking into account how active you are and if you are male or female.
You can input your information using metric or the US system of measurement (inches and pounds).
The program has an online help available and a special recource list to take your efforts further.

Calculations are based on Equations based on BMR. A much more accurate method for calculating TDEE is to determine basal metabolic rate (BMR) using multiple factors, including height, weight, age and sex, then multiply the BMR by an activity factor to determine TDEE. BMR is the total number of calories your body requires for normal bodily functions (excluding activity factors). This includes keeping your heart beating, inhaling and exhaling air, digesting food, making new blood cells, maintaining your body temperature and every other metabolic process in your body. In other words, your BMR is all the energy used for the basic processes of life itself.

BMR usually accounts for about two-thirds of total daily energy expenditure. BMR may vary dramatically from person to person depending on genetic factors. If you know someone who claims they can eat anything they want and never gain an ounce of fat, they have inherited a naturally high BMR. BMR is at it`s lowest when you are sleeping undisturbed and you are not digesting anything. It is very important to note that the higher your lean body mass is, the higher your BMR will be. This is very significant if you want to lose body fat because it means that the more muscle you have, the more calories you will burn. Muscle is metabolically active tissue, and it requires a great deal of energy just to sustain it.