If you're looking to lose weight, gain muscle, or simply maintain your current shape, understanding your BMR (Basal Metabolic Rate) is essential. A BMR Calculator helps you determine how many calories your body burns each day while at rest—just to keep you alive and functioning. It’s the foundation for building any effective diet or fitness plan.
At Calculators.at, our free BMR Calculator gives you instant results tailored to your age, gender, height, and weight, so you can take control of your energy balance and health goals.
BMR stands for Basal Metabolic Rate—the number of calories your body needs to perform basic life-sustaining functions like:
Even if you stayed in bed all day, your body would still burn calories to survive. That calorie count is your BMR.
A BMR Calculator estimates your basal energy needs using one of the most accurate formulas: the Mifflin-St Jeor Equation.
For Men:
BMR = 10 × weight (kg) + 6.25 × height (cm) – 5 × age (years) + 5
For Women:
BMR = 10 × weight (kg) + 6.25 × height (cm) – 5 × age (years) – 161
Once calculated, your BMR tells you how many calories you need daily just to survive—without any physical activity.
Understanding your BMR is the first step in managing your weight, because it helps you:
Use your BMR to calculate your TDEE, which determines how many calories you need to eat to maintain, lose, or gain weight.
A 30-year-old woman weighing 65 kg and standing 165 cm tall would have:
BMR = 10×65 + 6.25×165 – 5×30 – 161 = 650 + 1031.25 – 150 – 161 = 1,370.25
Her BMR is approximately 1,370 calories/day — this is how much her body burns at rest.
The BMR Calculator is one of the most important tools for anyone serious about health, fitness, or weight management. By understanding how your body works at rest, you gain the knowledge needed to create sustainable and realistic nutrition goals. Start with your BMR, then adjust your calorie intake based on your activity level to unlock better results.