BMR & Calorie Calculator
How many calories your body burns and how many you should eat for cut, maintain, or bulk — using the gold-standard Mifflin-St Jeor equation.
How to Use
Pick sex, then enter age, height (cm), and weight (kg). The Mifflin-St Jeor equation — the most accurate consensus formula — gives BMR.
Pick from 5 levels: sedentary (no exercise) → light (1–3×/week) → moderate (3–5×) → active (6–7×) → very active (intense daily or physical job). TDEE = BMR × activity multiplier.
BMR, TDEE, cut (−500 kcal), maintain, and bulk (+500 kcal) targets are shown together with protein and water recommendations based on body weight — ready for diet and meal planning.
FAQ
What's the difference between BMR and TDEE?
BMR (Basal Metabolic Rate): calories used just for staying alive — breathing, circulation, body temperature. TDEE (Total Daily Energy Expenditure): BMR + activity + exercise. Set diet targets relative to TDEE.
Why is Mifflin-St Jeor accurate?
Published 1990, it has the smallest error across diverse populations and is recommended by the American Dietetic Association (ADA). Formula — men: 10·kg + 6.25·cm − 5·age + 5; women: 10·kg + 6.25·cm − 5·age − 161.
How do I pick a cut target?
This tool recommends a safe deficit of TDEE − 500 kcal/day (~0.5 kg/week of fat loss). Larger deficits (−1000+) often cause muscle loss, plateaus, and metabolic adaptation. Eating below BMR is not recommended.
How do I choose activity level?
Sedentary (1.2): desk/remote work + no exercise. Light (1.375): walks or yoga 1–3×/week. Moderate (1.55): gym/running 3–5×. Active (1.725): hard training 6–7×. Very active (1.9): intense daily training or physical labor (moving, construction). Overestimating activity is the #1 reason fat loss stalls.
Where do protein and water recommendations come from?
Protein: 0.8 g/kg/day for sedentary adults; 1.6–2.2 g/kg/day for athletes per the International Society of Sports Nutrition (ISSN). This tool uses 1.6 g/kg (athlete baseline). Water: typical adult recommendation is 30–35 ml/kg; this tool uses 33 ml/kg.
How is this different from BMI?
BMI measures overweight/obese status from height and weight. BMR estimates daily calorie burn. Use BMI for body composition status; use BMR for diet calorie planning.
Is my input sent to a server?
No. All computation runs in your browser. Inputs are never sent over the network, never stored in localStorage or cookies.
