BMI Calculator
Check your Body Mass Index in secondsWhat Is a BMI Calculator?
A BMI (Body Mass Index) Calculator uses your height and weight to estimate whether your weight is healthy. BMI is a quick screening number used worldwide by doctors and health organizations. This tool shows your BMI on a color meter, tells you your category, and calculates your healthy weight range.
How to Use
- Choose Metric (kg and cm) or Imperial (lb, feet and inches).
- Enter your weight and height.
- Your BMI, category and healthy weight range appear instantly. No button needed.
BMI Formula
BMI = 703 × weight (lb) ÷ height (in)²
BMI Categories (WHO)
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25 – 29.9 | Overweight |
| 30 and above | Obese |
Example
BMI = 70 ÷ (1.70 × 1.70) = 24.2
Category: Normal weight
What Does This Tool Show?
- Your BMI score on a color meter
- Your weight category
- Healthy weight range for your height
- How much to gain or lose to reach the healthy range
- Metric and imperial units
- Free, no signup, private in your browser
Limitations of BMI
BMI is only a screening tool. It does not measure body fat directly and can be misleading for athletes and bodybuilders (muscle is heavy), older adults, and pregnant women. It is also not designed for children and teens under 18, who need age-based growth charts. For a full health check, talk to a doctor or dietitian.
Tips for a Healthy Weight
- Eat more vegetables, fruits and whole grains
- Walk or exercise at least 30 minutes a day
- Drink enough water and sleep 7–8 hours
- Limit sugary drinks and fried food
- Aim for slow, steady change, not crash diets
FAQ
What is a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered healthy.
Is BMI accurate for everyone?
No. It is a general guide. Muscle mass, age, gender and body type can affect how accurate it is.
Can children use this BMI calculator?
No. Children and teens need BMI-for-age percentile charts. Please ask a pediatrician.
Is my data saved?
No. All calculations happen in your browser.
How often should I check my BMI?
Once every month or two is enough. Weight changes slowly.
