Free BMI calculator — plus BMR, body fat & ideal weight
Calculate your Body Mass Index (BMI) in seconds — plus body-fat estimate, basal metabolic rate (BMR), and your healthy weight range. Works in metric (kg/cm) or imperial (lbs/ft-in). Everything is calculated privately in your browser: your data is never uploaded.
How to calculate your BMI
- Choose metric or imperial units.
- Enter your height and weight.
- Optionally enter your age and sex for extra metrics.
- Read your BMI score and category on the colour-coded scale.
- Review the body-fat, BMR and ideal-weight estimates.
Understanding your BMI result
BMI = weight (kg) ÷ height² (m). Categories:
- Under 18.5 — underweight.
- 18.5–24.9 — normal, healthy weight.
- 25–29.9 — overweight.
- 30+ — obese.
BMI is a screening tool, not a diagnosis
BMI doesn't distinguish muscle from fat, so very muscular people may score ‘overweight’ while being lean. Use it as one data point alongside body-fat percentage and waist measurement. Always consult a healthcare professional for medical decisions.
Medical disclaimer: The ToolCrix BMI calculator is provided for general informational and educational purposes only. The BMI categories shown follow the standard ranges published by the World Health Organization (WHO) and used by the US Centers for Disease Control and Prevention (CDC), but BMI, body-fat and BMR figures are estimates — they are not medical advice, and they cannot diagnose any health condition. Results may be misleading for athletes, older adults, pregnant women and children. Always consult a qualified healthcare professional before making decisions about your weight, diet or health.