BMI Calculator
Get a complete health overview from your height and weight. Add age, sex and activity level to see BMR + TDEE + 5 calorie targets. Optionally enter waist/hip/neck for waist-to-hip ratio and body-fat % (US Navy formula).
All calculations happen in your browser. No data is sent to a server.
These metrics are general indicators and not medical diagnoses. Consult a healthcare professional for medical advice.
How to use this bmi calculator
- Choose metric or imperial units and enter your height and weight.
- Add age, sex and activity level for BMR + TDEE + calorie targets.
- Optionally add waist, hip and neck measurements for body composition.
- Review BMI, BMI Prime, healthy weight range, ideal weight, daily calorie targets, water intake, waist-to-hip ratio and body-fat percentage.
Frequently asked questions
What is BMR vs TDEE?
BMR (basal metabolic rate) is calories burned at rest. TDEE multiplies BMR by an activity factor (1.2 sedentary → 1.9 very active) for total daily calorie burn.
How is body fat % calculated?
Using the US Navy formula: from height + waist + neck (and hip for women). It's an estimate accurate to ~3% for most people.
What is BMI Prime?
BMI divided by 25. Above 1.0 indicates overweight; under 0.74 indicates underweight. Quick way to see distance from healthy range.
Why is BMI inaccurate for athletes and bodybuilders?
BMI only uses height and weight, so muscle and fat weigh the same. A 90 kg sprinter with 8% body fat reads as 'overweight'; a 70 kg sedentary adult with 35% body fat can read as 'normal'. Use the body-fat % (Navy formula) and waist-to-hip ratio for a fuller picture.