BMR & TDEE Calculator

BMR & TDEE Calculator is a free online tool that estimates your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE), helping you understand how many calories your body needs each day. BMR represents the number of calories your body burns at complete rest just to maintain basic life-sustaining functions such as breathing, circulation, cell production, and temperature regulation. It accounts for approximately 60-75% of your total daily calorie expenditure, making it the single largest component of your energy budget. TDEE builds on your BMR by factoring in your physical activity level. While BMR measures energy expenditure at rest, TDEE gives you the total number of calories you burn in a typical day, including exercise, walking, and even the energy used to digest food (known as the thermic effect of food). Knowing your TDEE is essential for setting calorie targets — whether your goal is weight loss, muscle gain, or maintaining your current weight. To lose weight, you need to consume fewer calories than your TDEE; to gain weight, you need to consume more. This calculator uses the Mifflin-St Jeor equation, which is considered the most accurate BMR formula for most people according to the American Dietetic Association. It takes into account your weight, height, age, and gender to produce a personalized BMR estimate, then multiplies by an activity factor to calculate your TDEE. The tool also provides calorie targets for different goals, from aggressive weight loss (-20%) to weight gain (+20%). All calculations run entirely in your browser — no personal health data is sent to any server.