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BMR

BMR Calculator — Basal Metabolic Rate

Find out how many calories your body burns just to stay alive at complete rest — before any movement, exercise, or digestion is added — using the Mifflin-St Jeor equation.

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Enter your details to see your resting calorie burn
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Disclaimer: This calculator provides a general estimate for fitness-tracking and educational purposes only and is not medical advice. Individual metabolism varies with genetics, muscle mass, hormones, and health conditions. Consult a doctor or registered dietitian before making significant changes to your diet.

How BMR Is Calculated

Basal Metabolic Rate is the energy your body needs to keep essential functions running — heartbeat, breathing, brain activity, cell repair — while lying still and not digesting anything. It's the floor of your daily calorie needs, not a target to eat under. This calculator uses the Mifflin-St Jeor equation, widely regarded as the most accurate general-purpose BMR formula available today.

Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5

Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

What BMR Doesn't Include

BMR excludes digestion, walking, exercise, fidgeting, and every other form of daily movement — those are layered on top when you calculate your Total Daily Energy Expenditure (TDEE). Comparing your actual food intake against BMR alone will almost always suggest you're eating "too much," because it ignores the very real calories your daily activity burns.

Why Two Units — kcal and kJ

Most nutrition labels and calorie-tracking apps use kilocalories, but kilojoules are the standard energy unit on food packaging in several countries. This calculator shows both so the number matches whatever unit you're working with elsewhere.

Frequently Asked Questions

BMR is the calories your body needs just to stay alive at complete rest — breathing, circulation, cell repair, organ function. TDEE adds everything on top of that: digestion, daily movement, and exercise. BMR is always the smaller number and never a diet target on its own; TDEE is what you should compare your food intake against.
It's not advisable. Your BMR represents the minimum energy your organs need to function normally, and eating consistently below it can slow metabolism, disrupt hormones, and cause muscle loss rather than fat loss. Sustainable fat loss comes from a moderate deficit below TDEE, not below BMR.
Kilocalories (kcal, commonly just called "calories") are standard on nutrition labels in most countries, while kilojoules (kJ) are the metric energy unit used on food labels in Australia, New Zealand, and parts of Europe. Showing both lets you match whichever unit your food packaging or fitness app uses.
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