What are the BMI weight categories?

Under 18.5 is underweight, 18.5–24.9 is normal, 25–29.9 is overweight, and 30+ is obese, per WHO standard adult thresholds.

Is BMI accurate for everyone?

BMI doesn't account for muscle mass, bone density or body composition, so it can be misleading for athletes or older adults. Use it as a general screening tool, not a diagnosis.

BMI Calculator

Calculate Body Mass Index from height and weight.

How this is calculated

Metric: BMI = weight(kg) ÷ height(m)². Imperial: BMI = weight(lb) ÷ height(in)² × 703

About this calculator

The BMI calculator computes Body Mass Index from weight and height, in metric or imperial units, and shows the standard WHO weight category.

Worked example

70 kg, 170 cm

Result: BMI = 24.2 (Normal)

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Frequently asked questions

What are the BMI weight categories?

Is BMI accurate for everyone?

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