BMR (Basal Metabolic Rate) Calculator - Version 1.0 Basal Metabolic Rate is the number of calories your body needs when you are resting. Multiplied by your activity level, Basal Metabolic Rate lets you estimate how many calories you need to lose weight or maintain your current weight. BMR Calculator lets you calculate Basal Metabolic Rate without learning any math formulas. Just select your gender and activity level, enter your age, weight, and height. BMR Calculator supports both English and Metric measurements. You do not have to convert kilograms to pounds and wise versa. Just select the most convenient measurement system for you. Download BMR Calculator now.