Calorie / BMR Calculator
Estimate your BMR and TDEE with the Mifflin-St Jeor formula, then see daily calories to lose, gain, or maintain weight.
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Enter your details to see results.
Calorie / BMR Calculator
A calorie calculator tells you how many calories your body burns at rest (BMR) and in a normal day (TDEE), the two numbers that drive every weight goal. Numbrary uses the Mifflin-St Jeor equation — the most accurate standard formula — so the result reflects your real biology, not a rough guess.
Enter your sex, age, weight, and height, choose your activity level, and pick a goal (lose, maintain, or gain). The tool instantly shows your BMR, your TDEE, and the daily calorie target that matches your goal.
All math runs locally in your browser — nothing is uploaded and there is no signup. Pair it with the BMI calculator to get the full picture of your body composition and energy needs.
Frequently Asked Questions
What is BMR and how is it calculated?
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest. Numbrary uses the Mifflin-St Jeor equation: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + (5 for men, −161 for women).
What is TDEE?
TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor — from 1.2 for a sedentary lifestyle up to 1.9 for very intense training. It estimates your true daily burn.
How many calories to lose 1 kg per week?
One kilogram of fat is roughly 7,700 kcal, so losing 1 kg/week means a deficit of about 1,100 kcal/day. This calculator bakes that into the "Lose 1 kg/week" goal preset.
Are these numbers exact?
They are solid estimates, not medical precision. Real needs vary with body composition, hormones, and genetics. Use the result as a starting point and adjust based on actual progress.
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