BMI is your weight in kilograms divided by your height in metres, squared. For Pakistani and other South Asian adults, the World Health Organization advises treating a BMI of 23 or more as overweight and 27.5 or more as obesity, instead of the international 25 and 30.
Enter your height in feet and inches (or cm) and your weight in kg (or lb). The result shows both sets of categories, your healthy weight range and, if you add your waist, your waist-to-height ratio. The adult categories apply from age 18; for children the calculator shows the BMI only.
How to calculate BMI in kg and feet
The formula is BMI = weight (kg) ÷ height (m)². If you know your height in feet and inches, convert it first:
- Turn feet into inches: multiply the feet by 12 and add the inches.
- Turn inches into metres: multiply by 0.0254.
- Square the metres (multiply the number by itself).
- Divide your weight in kg by that figure.
In pounds and inches the formula is BMI = weight (lb) ÷ height (in)² × 703. The US Centers for Disease Control uses this example: 150 lb at 5 ft 5 in (65 inches) gives 150 ÷ 4,225 × 703 = 24.96.
Worked example
This is the example loaded above: a man of 5 ft 7 in weighing 72 kg.
| Step | Working | Result |
|---|---|---|
| Height in inches | 5 × 12 + 7 | 67 in |
| Height in metres | 67 × 0.0254 | 1.7018 m |
| Height squared | 1.7018 × 1.7018 | 2.896 |
| BMI | 72 ÷ 2.896 | 24.9 |
On the international scale, 24.9 is a healthy weight. On the WHO Asian scale it is overweight, because it is above 23. To come down to a BMI of 22.9 he would need to weigh about 66.3 kg, which is 5.7 kg less.
BMI categories: international and Asian
The first table is the WHO classification used worldwide. The second uses the public health action points from the WHO expert consultation on Asian populations published in The Lancet in 2004.
| BMI, WHO international | Category |
|---|---|
| Below 16 | Underweight (severe thinness) |
| 16 to 16.9 | Underweight (moderate thinness) |
| 17 to 18.4 | Underweight (mild thinness) |
| 18.5 to 24.9 | Healthy weight |
| 25 to 29.9 | Overweight (pre-obese) |
| 30 to 34.9 | Obesity class I |
| 35 to 39.9 | Obesity class II |
| 40 and above | Obesity class III |
| BMI, WHO Asian cut-offs | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 to 22.9 | Healthy weight (low risk) |
| 23 to 27.4 | Overweight (increased risk) |
| 27.5 and above | Obesity (high risk) |
The calculator classifies your exact BMI, so 24.98 is still healthy on the international scale even though it rounds to 25.0. When that happens it shows two decimals.
Why Pakistanis use lower BMI cut-offs
The 2004 WHO expert consultation found that many Asian populations carry more body fat, and have more type 2 diabetes and heart disease, at the same BMI as white Europeans. It kept the international categories but added lower action points at 23 and 27.5 for Asian populations. The UK's National Institute for Health and Care Excellence (NICE) uses the same 23 and 27.5 thresholds for adults of South Asian family origin.
Waist size tells you more about the fat around your organs. The International Diabetes Federation's cut-offs for South Asians are a waist of 90 cm (about 35.5 in) or more for men and 80 cm (about 31.5 in) or more for women. NICE also suggests keeping your waist to less than half your height, a waist-to-height ratio below 0.5.
Second example, with waist
A woman of 5 ft 2 in (157.5 cm) weighing 60 kg has a BMI of 24.2. That is healthy internationally but overweight on the Asian scale. Her waist is 34 in (86 cm), which is above the 80 cm level, and her waist-to-height ratio is 86 ÷ 157.5 = 0.55, in the increased risk band.
Healthy weight by height
Weights in kg for common heights. The Asian range tops out at a BMI of 22.9.
| Height | cm | Healthy, BMI 18.5 to 24.9 | Healthy, Asian 18.5 to 22.9 | Asian overweight from | Asian obesity from |
|---|---|---|---|---|---|
| 4 ft 10 in | 147 cm | 40.2 to 54.0 kg | 40.2 to 49.7 kg | 49.9 | 59.7 |
| 4 ft 11 in | 150 cm | 41.5 to 55.9 kg | 41.5 to 51.4 kg | 51.7 | 61.8 |
| 5 ft 0 in | 152 cm | 43.0 to 57.8 kg | 43.0 to 53.2 kg | 53.4 | 63.9 |
| 5 ft 1 in | 155 cm | 44.4 to 59.8 kg | 44.4 to 55.0 kg | 55.2 | 66.0 |
| 5 ft 2 in | 157 cm | 45.9 to 61.8 kg | 45.9 to 56.8 kg | 57.0 | 68.2 |
| 5 ft 3 in | 160 cm | 47.4 to 63.8 kg | 47.4 to 58.6 kg | 58.9 | 70.4 |
| 5 ft 4 in | 163 cm | 48.9 to 65.8 kg | 48.9 to 60.5 kg | 60.8 | 72.7 |
| 5 ft 5 in | 165 cm | 50.4 to 67.9 kg | 50.4 to 62.4 kg | 62.7 | 75.0 |
| 5 ft 6 in | 168 cm | 52.0 to 70.0 kg | 52.0 to 64.4 kg | 64.6 | 77.3 |
| 5 ft 7 in | 170 cm | 53.6 to 72.1 kg | 53.6 to 66.3 kg | 66.6 | 79.6 |
| 5 ft 8 in | 173 cm | 55.2 to 74.3 kg | 55.2 to 68.3 kg | 68.6 | 82.0 |
| 5 ft 9 in | 175 cm | 56.8 to 76.5 kg | 56.8 to 70.3 kg | 70.6 | 84.5 |
| 5 ft 10 in | 178 cm | 58.5 to 78.7 kg | 58.5 to 72.4 kg | 72.7 | 86.9 |
| 5 ft 11 in | 180 cm | 60.2 to 81.0 kg | 60.2 to 74.5 kg | 74.8 | 89.4 |
| 6 ft 0 in | 183 cm | 61.9 to 83.3 kg | 61.9 to 76.6 kg | 76.9 | 92.0 |
| 6 ft 1 in | 185 cm | 63.6 to 85.6 kg | 63.6 to 78.7 kg | 79.1 | 94.5 |
| 6 ft 2 in | 188 cm | 65.4 to 88.0 kg | 65.4 to 80.9 kg | 81.3 | 97.2 |
BMI for children and teenagers
Do not judge anyone under 18 by the adult ranges. Children's body fat changes as they grow and differs between boys and girls, so their BMI is compared with other children of the same age and sex on a BMI-for-age chart.
- The WHO growth reference for ages 5 to 19 counts a BMI-for-age above +1 standard deviation as overweight and above +2 as obesity.
- The US CDC charts use percentiles for ages 2 to 19: below the 5th percentile is underweight, the 5th to below the 85th is healthy, the 85th to below the 95th is overweight, and the 95th or above is obesity.
- Under 5, the WHO child growth standards are used instead.
This calculator shows a child's BMI but does not give a category. Ask your child's doctor to plot it on a growth chart.
What BMI does not tell you
BMI does not measure fat directly. A muscular person can have a high BMI with little fat, and an older person can have a normal BMI with too much fat and too little muscle. It also does not apply in pregnancy. For a better picture, add your waist measurement above or try the body fat calculator. To see a target weight worked out by four clinical formulas, use the ideal weight calculator.
This calculator gives an estimate from a published formula. It does not diagnose any condition and is not a substitute for a doctor. Talk to a doctor before making decisions about your health, diet or treatment.
BMI questions
What is a normal BMI for Pakistani adults?
On the WHO Asian cut-offs, 18.5 to 22.9 is the healthy range for Pakistani and other South Asian adults. From 23 the risk of diabetes and heart disease rises, and 27.5 or more counts as obesity. The international healthy range of 18.5 to 24.9 is still widely quoted, so this calculator shows both.
How do I calculate BMI with height in feet and weight in kg?
Multiply your feet by 12 and add the inches, then multiply by 0.0254 to get metres. Square that number and divide your weight in kg by it. For 5 ft 4 in and 60 kg: 64 in is 1.6256 m, squared is 2.643, and 60 ÷ 2.643 gives a BMI of 22.7.
Is the BMI calculator different for men and women?
No. Adults use the same formula and the same categories whatever their sex. Women usually carry more body fat than men at the same BMI, which is one reason waist size and body fat percentage are worth checking too. Sex matters for children, whose BMI is read from separate charts for boys and girls.
What BMI is considered obese?
Internationally, a BMI of 30 or more is obesity, split into class I (30 to 34.9), class II (35 to 39.9) and class III (40 and above). For South Asian adults WHO and NICE use a lower threshold of 27.5. A doctor will also look at your waist, blood pressure, blood sugar and family history.
Can I use this BMI calculator for my child?
You can use it to work out the number, but not the category. For anyone under 18, BMI has to be compared with other children of the same age and sex on a BMI-for-age chart. The calculator shows the BMI without a label for anyone under 18. Your child's doctor can read it on a WHO or CDC chart.
Is BMI accurate?
BMI is a quick screening number, not a diagnosis. It works well across large groups but can mislead for one person. It overstates fat in very muscular people and can understate it in older adults and in many South Asians. Waist-to-height ratio and body fat percentage give a fuller picture.
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Last reviewed 30 September 2026. Results are estimates; official notices always take precedence.