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BMI calculator – body mass index for adults

Enter your weight and height in kg and cm, or pounds and feet, to get your BMI and the WHO adult category. Includes the BMI chart and Asian-Indian cut-offs.

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BMI calculator

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Units

22.9

Normal range

Adult BMI bands from the WHO: under 18.5 underweight, 18.5 to 24.9 normal range, 25 to 29.9 overweight, 30 and over obese. This is a screening guide, not a diagnosis.

How to use the bmi calculator

  1. Choose metric (kg, cm) or imperial (lb, feet and inches).

  2. Enter your weight and height.

  3. Read your BMI and its category on the chart below.

  • No uploadYour files are processed on your device and never sent anywhere.
  • FastNo upload or download wait – results appear in seconds.
  • Free, no signupNo account, no watermark and no daily limit.

BMI calculator: check your body mass index

Enter your weight and height, in kg and cm or pounds, feet and inches, and the BMI calculator shows your body mass index and the WHO adult category straight away. BMI is weight in kilograms divided by height in metres squared. It is a quick screen for whether weight is in a healthy range for your height. Your figures stay in this tab.

BMI chart for adults

BMI WHO category Asian-Indian cut-offs*
Below 18.5 Underweight Underweight
18.5 – 22.9 Normal Normal
23 – 24.9 Normal Overweight
25 – 29.9 Overweight Obese
30 and above Obese Obese

*Indian consensus guidelines and WHO’s advice for Asian populations use lower thresholds because risks such as diabetes rise at a lower BMI. The calculator result uses the WHO column.

BMI formula and example

BMI = weight (kg) ÷ height (m)²

5 ft 7 in is 1.70 m. At 70 kg: 70 ÷ (1.70 × 1.70) = 24.2. That is normal on the WHO chart and overweight on the Asian-Indian cut-offs.

Tips

  • Measure height without shoes and weight in the morning for a consistent reading.
  • BMI can overstate risk for muscular people and understate it for older adults.
  • For children, use an age-and-sex BMI percentile chart instead.

This is a screening tool, not medical advice.

Convert feet to centimetres or pounds to kilograms with the unit converter. Check your exact age with the age calculator.

Frequently asked questions

What is a normal BMI?

For adults, WHO puts the normal range at 18.5 to 24.9. Under 18.5 is underweight, 25 to 29.9 is overweight and 30 or more is obese.

Is the normal BMI different for Indians?

Indian consensus guidelines and WHO’s advice for Asian populations use lower cut-offs because health risk rises at a lower BMI: 23 to 24.9 is treated as overweight and 25 or more as obese. This calculator shows the WHO bands. Ask your doctor which applies to you.

How is BMI calculated?

BMI = weight in kg ÷ (height in metres)². 70 kg at 1.70 m is 70 ÷ 2.89 = 24.2.

Is BMI the same for men and women?

The adult formula and bands are the same for both. BMI does not separate muscle from fat, so it can mislead for athletes and older adults.

Can I use this for a child?

No. Children and teenagers use BMI-for-age percentiles, not these adult bands.

Is BMI a diagnosis?

No. It is a quick screen. Waist size, blood tests and a clinician’s view give a fuller picture.

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