⚖️ BMI Calculator

Calculate your Body Mass Index instantly. Supports metric, imperial, and UK (stones/lbs) units. Choose standard WHO or Asian WHO Asia-Pacific cutoffs. Includes waist-to-height ratio, healthy weight range, and age-specific guidance.

BMI Calculator

Weight (kg)

70 kg

Height (cm)

170 cm

Gender (for healthy weight range)

Age (optional)

Population Standard

Waist circumference (cm, optional)

📈 Results

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UnderweightNormalOverweightObese

< 18.5

18.5–25

25–30

> 30

Healthy Weight Range

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Weight to Lose/Gain

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BMI Prime

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Ponderal Index

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Waist-to-Height Ratio

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BMI Gauge

Weight Comparison

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Enter Details

Enter your weight and height to calculate BMI

Formula

Understanding BMI

BMI Formula

BMI = Weight (kg) ÷ Height (m)²

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BMI Categories (WHO)

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Limitations of BMI

BMI doesn't distinguish between muscle and fat. Athletes may have high BMI despite low body fat. Elderly may have normal BMI but high fat percentage. Use BMI along with waist circumference and body fat % for a complete picture.

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Asian BMI Cutoffs

For South Asian and East Asian populations, health organizations recommend lower cutoffs: Overweight at BMI 23+, Obese at BMI 27.5+. Select "Asian (WHO Asia-Pacific)" in the Population Standard field above to apply these corrected cutoffs.

FAQ

Frequently Asked Questions

Common questions about BMI calculations

Is BMI an accurate measure of health?

BMI is a useful screening tool but not a diagnostic measure. It doesn't account for age, sex, muscle mass, bone density, or fat distribution. A person with high muscle mass may have a "overweight" BMI while being very fit. Always consult a doctor for a complete health assessment.

What is BMI Prime?

BMI Prime is your BMI divided by the upper threshold of normal BMI (25). A BMI Prime of 1.0 means you're at exactly the upper limit of normal. Values below 1.0 are normal weight or below; values above 1.0 indicate overweight or obese. It allows easy comparison regardless of the specific BMI value.

What is a healthy BMI for women vs men?

The WHO uses the same BMI categories for both men and women (18.5–24.9 for normal weight). However, women naturally have higher body fat percentages than men at the same BMI. Some health organizations suggest women may be healthy at slightly lower BMI values than men.

How can I reach a healthy BMI?

Sustainable approaches include: combining moderate caloric deficit with regular physical activity (150+ min/week cardio + strength training), focusing on nutrient-dense whole foods, adequate protein intake (1.2–1.6g per kg / 0.54–0.73g per lb body weight), sufficient sleep (7-9 hours), and managing stress. Avoid extreme diets — gradual changes are more sustainable.