My calculators are based on the Harris-Benedict formula for determining your basal metabolic rate (BMR), plus your active metabolic rate (AMR), which is based on your estimation of your daily physical activity.
Basal Metabolic Rate
Women: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)
Men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in years)
Active Metabolic Rate
Calculate your AMR by using your BMR and estimating your current level of activity. If you are:
- Sedentary (little or no exercise) - your AMR = BMR x 1.2
- Lightly active (light exercise/work 1-3 days per week) - your AMR = BMR x 1.375
- Moderately active (moderate exercise/work 3-5 days per week) - your AMR = BMR x 1.55
- Very active (hard exercise/work 6-7 days a week) - your AMR = BMR x 1.725
- Extra active (very hard exercise/work 6-7 days a week) - your AMR = BMR x 1.9
Academy of Nutrition and Dietetics. "In non-obese individuals, what is the prediction accuracy and maximum overestimation and underestimation errors compared to measured resting metabolic rate when using the Harris-Benedict formula?" Academy of Nutrition and Dietetics Evidence Analysis Library. Published March 2005.
"Food Intake Patterns." United States Department of Agriculture. Center for Nutrition Policy and Promotion. Accessed May 10, 2011. http://www.mypyramid.gov/downloads/MyPyramid_Food_Intake_Patterns.pdf.