BMI Calculator
Calculate your Body Mass Index in metric (kg/cm) or imperial (lbs/ft) units. Instantly see your BMI score and weight category.
Quick BMI Check in Any Unit
Metric or imperial — instant BMI calculation with clear category classification.
Metric & Imperial
Switch between kg/cm and lbs/ft instantly. No manual unit conversion needed.
WHO Categories
Result includes WHO weight category — underweight, normal, overweight, or obese.
Visual Scale
Color-coded BMI scale shows where your result falls at a glance.
Instant Calculation
No server round-trip. BMI calculated in milliseconds directly in your browser.
Private & Secure
Health data stays on your device — nothing is sent to any server.
Always Free
No account, no paywall. Calculate BMI as many times as you need.
Who Uses This Tool
Individuals, fitness professionals, and healthcare students alike.
Personal Health Tracking
Monitor your BMI over time to understand how your weight relates to your height.
- Track BMI changes over months
- Set weight goals based on healthy range
- Understand underweight vs. overweight thresholds
Fitness & Nutrition
Use BMI as one of several metrics when planning fitness or diet programmes.
- Baseline metric for client assessments
- Progress tracking for weight-loss clients
- Quick pre-screening reference
Healthcare & Education
Students and clinicians use BMI as a standard screening metric in assessments.
- Standard WHO classification reference
- Quick calculation for student exercises
- Both unit systems for international study
How to Calculate BMI
Select your preferred unit system — metric (kg and cm) or imperial (lbs and feet/inches).
Enter your weight and height in the corresponding fields.
Click Calculate to see your BMI score and weight category with a color-coded scale.
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Frequently Asked Questions
Common questions about Body Mass Index and how to interpret your result.
What is BMI?
BMI (Body Mass Index) is a number calculated from your weight and height. It is widely used as a screening tool to identify possible weight-related health risks. BMI = weight(kg) ÷ height(m)².
What is a healthy BMI?
According to the WHO, a BMI between 18.5 and 24.9 is considered normal/healthy. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese.
Is BMI accurate for everyone?
BMI is a general screening tool and has limitations. It does not account for muscle mass, bone density, age, or fat distribution. Athletes may have a high BMI without being overweight. Consult a healthcare professional for a full assessment.
How is BMI calculated in imperial units?
Imperial BMI = (weight in lbs ÷ height in inches²) × 703. For example, a person who is 5'10" (70 inches) and 160 lbs: BMI = (160 ÷ 4900) × 703 ≈ 22.9.