BMI and Health Calculator
Estimate your BMI, WHO weight category, healthy weight range, waist-based health risk and daily energy needs in kilojoules and kilocalories.
Optional but improves the risk estimate.
Your results
Assumptions
- BMI is a population screening tool, not medical advice. It does not account for muscle mass, pregnancy, ethnicity or overall body composition — see a health professional for personal advice.
- Daily energy needs use the Mifflin-St Jeor equation multiplied by an activity factor, and are an estimate only.
- The healthy weight range is based on a BMI of 18.5 to 24.9 for your entered height.
How this calculator works
Enter your height, weight, age, sex, waist measurement and activity level to see your BMI, WHO weight category, a healthy weight range for your height, a waist-based health risk note, and estimated daily energy needs using the Mifflin-St Jeor equation.
Frequently asked questions
Is BMI accurate for everyone?
No. BMI is a population screening tool and does not account for muscle mass, pregnancy, ethnicity or overall body composition. It should not replace professional medical advice.
How is the healthy weight range worked out?
It uses the WHO healthy BMI band of 18.5 to 24.9, applied to your entered height.
What activity factor should I choose?
Pick the option that best matches your typical weekly exercise — this scales your estimated energy needs above your resting metabolic rate.