What is a healthy BMI?

A healthy BMI for adults is 18.5–24.9. Below 18.5 is underweight, 25–29.9 is overweight, 30+ is obese.

How is BMI calculated?

BMI = weight (kg) ÷ height² (m²). Imperial: (weight lbs × 703) ÷ height² (in²).

Is BMI accurate for everyone?

BMI is a useful screening tool but doesn't account for muscle mass, bone density, age, or ethnicity.

BMI Calculator — Free Body Mass Index Check

BMI Calculator

🎙️ Voice Input

Say: "height 175, weight 70"

📏 Height

Enter height (50–250 cm)

📏 Height

⚖️ Weight

Enter weight (10–500 kg)

⚖️ Weight

lbs

🎂 Age (optional)

yrs

👤 Sex (optional)

BMI SCALE

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1018.52530354050

🎯

Ideal Weight

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BMI 18.5–24.9

🔥

Daily Calories

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Resting + active

📐

Ponderal Index

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kg/m³

⚖️

Fat Mass Est.

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Based on BMI

💪

Lean Mass Est.

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Muscle + bone

📊

Weight Status

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vs. healthy range

Category	BMI Range	Health Risk
Underweight	< 18.5	Malnutrition risk
Normal Weight	18.5 – 24.9	Low (healthy)
Overweight	25 – 29.9	Increased
Obese Class I	30 – 34.9	Moderate
Obese Class II	35 – 39.9	Severe
Obese Class III	≥ 40	Very Severe

🌿 Wellness Tips

❓ Frequently Asked Questions

What Is BMI & How Is It Calculated?

Body Mass Index (BMI) is a widely used screening tool that estimates body fat based on height and weight. Developed by Adolphe Quetelet in the 19th century, it remains a key metric used by the WHO, CDC, and healthcare providers globally.

The BMI Formula

Metric: BMI = weight (kg) ÷ height² (m²) | Imperial: BMI = (weight lbs × 703) ÷ height² (in²)

BMI Limitations

BMI doesn't account for muscle mass, bone density, ethnicity, age, or sex. Athletes may show a high BMI despite low body fat. Use it alongside other indicators and consult a healthcare professional for a complete assessment.

Athletes may show high BMI despite low body fat due to muscle mass
Older adults may have normal BMI but excess body fat (sarcopenic obesity)
Asian populations face health risks at lower BMI thresholds (overweight ≥23)
Pregnant women should not use standard BMI classifications

⚕️ Medical Disclaimer: This BMI calculator is for informational purposes only and does not constitute medical advice. Please consult a qualified healthcare professional for personalized guidance.

Free Body Mass Index Calculator