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BMI calculator

Body mass index for adults, in pounds and feet or kilograms and centimeters.

Height

For adults 20 and over. BMI is a screening measure, not a diagnosis.

Your BMI

23.6

Normal weight

Healthy weight for your height
125.3 to 168.6 lb

How we got this

  1. Height in inches: 5 ft × 12 + 9 in = 69 in
  2. In meters (1 in = 0.0254 m): 69 × 0.0254 = 1.7526 m
  3. Weight in kilograms (1 lb = 0.45359237 kg): 160 × 0.45359237 = 72.574779… kg
  4. Square the height: 1.7526 × 1.7526 = 3.071607…
  5. Divide the weight by it: 72.574779… ÷ 3.071607… = 23.627627…, or 23.6 to one decimal

Worked out on your device. Nothing is sent anywhere.

BMI categories for adults

BMICategory (WHO)
Below 18.5Underweight
18.5 to 24.9Normal weight
25.0 to 29.9Pre-obesity (overweight)
30.0 to 34.9Obesity class I
35.0 to 39.9Obesity class II
40.0 and aboveObesity class III

The categories are the World Health Organization’s and the same ones the CDC uses for adults (the CDC calls 18.5 to 24.9 “healthy weight” and 25 to 29.9 “overweight”). They describe risk across large groups of people; your own risk depends on much more than one number.

Questions

How is BMI calculated?

Body mass index is weight in kilograms divided by height in meters squared. At 70 kg and 1.75 m: 70 ÷ (1.75 × 1.75) = 22.9. In US units the calculator converts exactly (1 lb = 0.45359237 kg, 1 inch = 2.54 cm) rather than using the common shortcut 703 × pounds ÷ inches², which can differ in the first decimal.

What is a healthy BMI?

For adults, the World Health Organization classes 18.5 to 24.9 as normal weight, 25 to 29.9 as pre-obesity (overweight) and 30 or more as obesity, in three classes. Below 18.5 is underweight. The calculator also shows the range of weights that gives a BMI of 18.5 to 24.9 at your height.

Is BMI accurate for everyone?

No. BMI is a quick screening number, not a diagnosis. It doesn’t tell muscle from fat, so very muscular people can score high, and it can underestimate body fat in older adults. Some health bodies use lower cut-offs for people of Asian descent. A doctor can look at waist size, body composition and health history as well.

Can I use this for children or teenagers?

No. Under 20 (in the US) or 18 (WHO), BMI is judged against growth charts for the child’s age and sex, as a percentile. Use a BMI-for-age calculator from the CDC or your pediatrician instead.

Why does my BMI show one decimal?

Because the categories are defined to one decimal (24.9, then 25.0). The category always matches the number shown: a BMI of 24.96 shows as 25.0, which is in the pre-obesity range.

Is my weight saved or sent anywhere?

No. The calculation happens in your browser and nothing is sent anywhere. Your entries appear in the page address only so you can bookmark the result.

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