BMR Calculator
Calculate your basal metabolic rate with the Mifflin-St Jeor equation (1990) — the calories your body burns at complete rest every day.
Mifflin–St Jeor equation (1990): 10 × kg + 6.25 × cm − 5 × age + 5 for men, − 161 for women, with weight in kg and height in cm. Activity multipliers 1.2–1.9 and the ±500 kcal goal adjustment are standard TDEE heuristics.
This tool runs entirely in your browser. Your data never leaves your device — it is not uploaded to any server.
How to use
- 1Choose your sex and metric (cm + kg) or imperial (ft + in + lb) units.
- 2Enter your height, weight and age.
- 3Read your BMR in kilocalories per day.
- 4Feed it into the calorie calculator to get maintenance and goal targets.
BMR Calculator
Your basal metabolic rate (BMR) is the energy your body spends just staying alive — breathing, circulating blood, keeping warm — before any movement or digestion. This calculator uses the Mifflin-St Jeor equation, published in 1990 and still the most accurate widely used predictor for modern populations: men 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5; women the same expression minus 161.
Enter your details in metric or imperial units and the result updates as you type. Treat the number as a population-level estimate — typically within about ±10% of a lab measurement — not a medical diagnosis.
Frequently asked questions
Which formula does this use, and how accurate is it?
The Mifflin-St Jeor equation, published in 1990 and recommended by the American Dietetic Association after validation against indirect calorimetry. It predicts measured resting energy expenditure within roughly ±10% for most adults, more accurately than the older Harris-Benedict equation (1919).
What is the difference between BMR and daily calorie needs?
BMR covers complete rest only. Your real daily burn is BMR multiplied by an activity factor — about 1.2 for a sedentary day up to 1.9 for very active people. The calorie calculator applies that multiplier and your goal for you.
Is this medical advice?
No — this is an estimate, not medical advice. Illness, medication, pregnancy and unusual body compositions all shift real energy expenditure, so discuss any diet change with a healthcare professional.
Related tools
Calorie Calculator
Turn your BMR into daily calorie targets: five activity levels (×1.2–1.9) plus lose, maintain or gain goals of about ±500 kcal a day.
All tools →
BMI Calculator
Calculate Body Mass Index from metric or imperial inputs and see exactly where the value lands in the official WHO weight categories.
All tools →
Body Fat Calculator
Estimate body fat percentage with the US Navy tape method (Hodgdon & Beckett, 1984) from height, neck and waist — hips for women.
All tools →
Ideal Weight Calculator
See your ideal weight from the Devine formula (1975) and the healthy BMI band (18.5–24.9) for your height, shown in kg or pounds.
All tools →
Embed this tool
Put this tool on your own site with one line — it runs entirely in the visitor's browser.
<iframe src="https://zoyku.com/en/tools/bmr-calculator?embed=1" width="100%" height="640" style="border:0;border-radius:16px" title="Zoyku — bmr-calculator" loading="lazy"></iframe>