BMR Calculator
Determine your Basal Metabolic Rate—the calories your body needs at complete rest.
If Body Fat is provided, we use the Katch-McArdle formula. Otherwise, we use the Mifflin-St Jeor equation.
Understanding Basal Metabolic Rate (BMR)
BMR stands for Basal Metabolic Rate. It represents the number of calories your body needs to perform basic, life-sustaining functions while at rest. These functions include breathing, blood circulation, nutrient processing, and cell production.
BMR is often referred to as your body's metabolism. It accounts for about 60% to 75% of the calories you burn each day. Factors that influence your BMR include age, gender, weight, height, and body composition.
Mifflin-St Jeor Equation vs. Katch-McArdle Formula
Our calculator automatically selects the most accurate formula based on the data you provide:
- Mifflin-St Jeor Equation: This is the modern gold standard for estimating BMR. It takes into account your weight, height, age, and gender. It is highly accurate for the general population.
- Katch-McArdle Formula: This formula requires your body fat percentage. It is often considered more accurate for lean individuals because it calculates metabolism based on lean body mass rather than total weight.
BMR vs. TDEE
It is important to note that BMR is not the same as TDEE (Total Daily Energy Expenditure). TDEE includes the calories burned during physical activity and the digestion of food (Thermic Effect of Food). Your BMR is strictly the calories burned at rest.