BMI Calculator
Calculate your Body Mass Index quickly
How to Use BMI Calculator
- 1Select your unit system (Metric or Imperial)
- 2Enter your height in the appropriate fields
- 3Enter your current weight
- 4Click "Calculate BMI" to see your result
- 5Review the BMI category and health interpretation
About BMI Calculator
Body Mass Index (BMI) is a simple calculation used to assess whether a person has a healthy body weight relative to their height. Our BMI Calculator provides instant results with detailed health interpretations.
BMI is calculated by dividing weight in kilograms by the square of height in meters (BMI = kg/m²). The tool supports both metric (kg/cm) and imperial (lbs/ft) measurements.
Key Features of BMI Calculator
- Calculate BMI using metric (kg/cm) or imperial (lbs/ft) units
- Instant BMI classification (Underweight, Normal, Overweight, Obese)
- Visual BMI scale with color-coded ranges
- Healthy weight range calculator for your height
- Track BMI changes over time
- Age and gender considerations for interpretation
- Mobile-friendly design for on-the-go calculations
- No data storage — calculations are private
Examples
Calculate BMI for an adult using metric units
A common scenario for tracking fitness goals or health check-ups.
Input
Height: 175 cm, Weight: 75 kg
Output
BMI: 24.5 — Normal weight
Calculate BMI using imperial units
Useful for users in the United States who prefer pounds and feet.
Input
Height: 5 ft 9 in, Weight: 185 lbs
Output
BMI: 27.3 — Overweight
Common Use Cases
- Assessing personal health status during fitness journeys
- Monitoring weight changes during diet programs
- Healthcare professionals screening patients
- Personal trainers setting client goals
- Insurance applications requiring BMI documentation
- School health programs tracking student wellness
Troubleshooting
BMI seems inaccurate for my body type
Solution
BMI doesn't account for muscle mass. Athletes and muscular individuals may have high BMI despite low body fat. Consider body fat percentage measurements for a complete picture.
My BMI is high but I'm healthy
Solution
BMI is a screening tool, not a diagnostic. Factors like age, muscle mass, bone density, and ethnicity affect interpretation. Consult a healthcare provider for personalized assessment.
The healthy weight range seems too wide
Solution
The healthy BMI range (18.5-24.9) covers a broad spectrum. Your ideal weight depends on factors like frame size, muscle mass, and personal health goals.
Frequently Asked Questions
What is BMI?
BMI (Body Mass Index) is a measure of body fat based on height and weight. It's used by healthcare professionals as an indicator of healthy weight ranges.
What is a healthy BMI range?
A BMI between 18.5 and 24.9 is considered healthy. Under 18.5 is underweight, 25-29.9 is overweight, and 30 or above is obese.
Is BMI accurate for everyone?
BMI is a general indicator and may not be accurate for athletes, elderly people, or pregnant women. Always consult a healthcare professional for personalized advice.
How is BMI calculated?
In metric units, BMI = weight (kg) ÷ height (m)². In imperial units, BMI = (weight (lbs) ÷ height (in)²) × 703. Both formulas produce the same result when units are consistent.
Can BMI be used for children?
Child BMI uses age- and sex-specific percentile charts rather than the fixed adult ranges. This tool is designed for adults aged 18 and over and should not be used to assess children's weight status.
Is my data saved or sent anywhere?
No. All calculations happen entirely in your browser using JavaScript. Your height and weight values are never transmitted to any server and are cleared when you close the page.
Why does my BMI not change the category even though I lost weight?
BMI categories span several points on the scale, so small weight changes may not cross a category boundary. Even within the same category, weight loss has measurable health benefits — track trends over time rather than focusing solely on category labels.
What is the difference between BMI and body fat percentage?
BMI is a simple ratio of weight to height and does not directly measure body fat. Body fat percentage requires tools like DEXA scans or calipers. Two people with the same BMI can have very different body compositions.