Work out BMI from height and weight in cm and kg, or ft, in and lb. Runs on your device.
BMI is weight in kilograms divided by height in metres squared. At 170 cm and 65 kg the height is 1.7 m, 1.7 × 1.7 = 2.89, and 65 ÷ 2.89 = 22.49, shown as 22.5. In imperial units the page first converts: inches are multiplied by 0.0254 to get metres and pounds by 0.45359237 to get kilograms, then the same formula is used. 5 ft 7 in is 67 in, which is 1.7018 m, and 154 lb is 69.85 kg, giving 24.1. The box under the answer repeats every step with your own numbers. Heights from 100 to 250 cm (3 to 8 ft) and weights from 20 to 500 kg (44 to 1100 lb) are accepted.
The categories follow the World Health Organization's adult table: underweight below 18.5, normal weight 18.5 to 24.9, overweight 25 to 29.9, obesity class I 30 to 34.9, class II 35 to 39.9 and class III 40 or more. The category is read from the BMI as shown, rounded to 1 decimal, so a BMI of 24.97 is shown as 25.0 and falls in overweight; what you see and the category always agree. The page also shows the weight that gives a BMI of 18.5 to 24.9 at your height: weight = BMI × height². At 170 cm that is 53.5 to 72.0 kg.
This page is for adults aged 18 and over. For children and teens BMI is read against growth charts for their age and sex, which this page does not have, so choosing Under 18 shows a message and no result. BMI uses only height and weight. It does not account for muscle, age, sex or ethnicity, and it does not measure body fat or where fat sits. It is a screening number, not a diagnosis. A health professional looks at much more than this figure.
Some health bodies use different cut-offs for some populations, most often lower ones for people of Asian ancestry. This page shows only the WHO adult categories above and does not change them for any group. Pregnancy, older age, very muscular builds and some medical conditions also change how a BMI is read. The numbers here come only from what you type and are rounded for display, and a BMI is not a diagnosis.
Convert height to metres (inches × 0.0254) and weight to kilograms (pounds × 0.45359237), then divide weight by height squared. For 5 ft 7 in and 154 lb that is 69.85 ÷ 2.896 = 24.1. Choose ft, in, lb and the page does the conversion and shows it.
On the WHO adult table, normal weight is a BMI from 18.5 to 24.9. At 170 cm that is a weight from 53.5 to 72.0 kg, which the page shows for your own height. Below 18.5 is underweight, 25 to 29.9 overweight and 30 or more is obesity class I, II or III.
No. Under 18, BMI is compared with growth charts for the child's age and sex, and the adult categories do not apply. Choose Under 18 and the page shows a message instead of a number.
Yes, some use lower cut-offs for people of Asian ancestry. The World Health Organization has described extra action points at 23 and 27.5 for these populations. This page uses only the standard WHO adult categories and does not change them.
It uses only height and weight. A muscular person can have a BMI above 25 with little body fat, and an older person can have a normal BMI with little muscle. It does not account for muscle, age, sex or ethnicity, so it is a screening number and not a diagnosis.
No. The numbers stay in this tab and are not stored on your device or sent anywhere. Reloading the page puts the example back. The page only counts that a result was shown, without any of your numbers.