BMI & calorie calculator
Enter your height and weight in metric or imperial to get your BMI, a healthy weight range for your height, and an estimate of daily calorie needs.
Calculated in your browser and never stored. For information only — not medical advice.
BMI categories
| BMI | Category (adults) |
|---|---|
| Under 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and over | Obese |
These are the World Health Organization and Health Canada adult categories. BMI is a quick screening number, not a diagnosis: it doesn’t distinguish muscle from fat, and it isn’t meant for children, pregnant people or very muscular athletes. Talk to a health professional about your own situation.
Formulas used
- BMI = weight (kg) ÷ height (m)². In imperial: 703 × weight (lb) ÷ height (in)².
- BMR (Mifflin-St Jeor): 10 × kg + 6.25 × cm − 5 × age + 5 for men, or − 161 for women.
- Maintenance calories = BMR × activity factor (1.2 to 1.9).
A loss of about 0.5 kg (1 lb) a week corresponds to a deficit of roughly 500 kcal a day. Need to switch between kilograms and pounds? Use the kg to lbs converter.
Frequently asked questions
What is a healthy BMI?
For adults, 18.5 to 24.9 is classed as a normal weight.
Is BMI accurate?
It’s a useful population-level screening tool but can misclassify individuals, especially athletes with lots of muscle, older adults and some ethnic groups.
How many calories should I eat?
Your maintenance estimate is shown above. Individual needs vary by 10% or more, so track your weight for a few weeks and adjust.
Does this work for children?
No. Children and teens need age- and sex-specific BMI percentiles, which a doctor can provide.