BMI Calculator in kg and Feet: Formula & Indian BMI Chart
Work out BMI from weight in kg and height in feet and inches, see the Asian cut-off of 23, a height-weight chart, and how BMI works for kids.
To calculate BMI from weight in kg and height in feet, first convert your height to metres, then divide your weight by the height squared:
- Height in metres = (feet × 12 + inches) × 0.0254
- BMI = weight (kg) ÷ height (m)²
For example, 65 kg at 5 feet 6 inches: 5 × 12 + 6 = 66 inches, × 0.0254 = 1.676 m. 1.676² = 2.81. BMI = 65 ÷ 2.81 = 23.1. Our BMI calculator takes height in centimetres, so enter 167.6 cm (feet × 30.48 + inches × 2.54).
BMI is a screening number only. It is not a diagnosis; speak to a doctor about your own health.
The BMI formula
BMI = weight in kilograms ÷ (height in metres × height in metres)
The same formula is used for men and women. If you know your height in centimetres, divide by 100 to get metres. If you use pounds and inches, the formula is BMI = 703 × pounds ÷ inches².
Converting feet and inches
| Height | Inches | Centimetres | Metres |
|---|---|---|---|
| 5 ft 0 in | 60 | 152.4 | 1.524 |
| 5 ft 2 in | 62 | 157.5 | 1.575 |
| 5 ft 4 in | 64 | 162.6 | 1.626 |
| 5 ft 6 in | 66 | 167.6 | 1.676 |
| 5 ft 8 in | 68 | 172.7 | 1.727 |
| 5 ft 10 in | 70 | 177.8 | 1.778 |
| 6 ft 0 in | 72 | 182.9 | 1.829 |
Worked examples
80 kg, 5 ft 9 in
- 69 inches × 0.0254 = 1.753 m
- 1.753² = 3.072
- BMI = 80 ÷ 3.072 = 26.0
55 kg, 5 ft 2 in
- 62 inches × 0.0254 = 1.575 m
- 1.575² = 2.480
- BMI = 55 ÷ 2.480 = 22.2
BMI categories: WHO vs Asian cut-off of 23
There are two sets of adult cut-offs in common use.
| Category | General WHO cut-offs | Indian / Asian cut-offs |
|---|---|---|
| Underweight | Below 18.5 | Below 18 (18.5 is also commonly used) |
| Normal | 18.5 – 24.9 | 18 – 22.9 |
| Overweight | 25 – 29.9 | 23 – 24.9 |
| Obese | 30 and above | 25 and above |
Research summarised by WHO's expert consultation on Asian populations, and Indian consensus guidelines published in 2009, found that South Asian adults tend to carry more body fat and develop diabetes and heart disease at lower BMIs than Europeans. That is why Indian doctors often treat 23 as the start of overweight and 25 as obese, instead of 25 and 30.
So the 65 kg, 5 ft 6 in example above (BMI 23.1) is "normal" on the WHO scale but "overweight" on the Indian scale.
Our BMI calculator labels results using the general WHO categories and shows a healthy weight range based on 18.5 to 24.9. If you are using the Asian cut-offs, compare your number with the right-hand column of the table above.
Height and weight chart (feet, kg)
Weight ranges for adults by height, rounded to the nearest 0.1 kg.
| Height | BMI 18.5 | BMI 22.9 (Asian upper normal) | BMI 24.9 (WHO upper normal) |
|---|---|---|---|
| 5 ft 0 in | 43.0 kg | 53.2 kg | 57.8 kg |
| 5 ft 2 in | 45.9 kg | 56.8 kg | 61.8 kg |
| 5 ft 4 in | 48.9 kg | 60.5 kg | 65.8 kg |
| 5 ft 6 in | 52.0 kg | 64.4 kg | 70.0 kg |
| 5 ft 8 in | 55.2 kg | 68.3 kg | 74.3 kg |
| 5 ft 10 in | 58.5 kg | 72.4 kg | 78.7 kg |
| 6 ft 0 in | 61.9 kg | 76.6 kg | 83.3 kg |
To find the weight for any BMI and height: weight = BMI × height (m)².
BMI for men and women by age
For adults (18 and over), BMI does not change with age or sex. A 25-year-old woman and a 60-year-old man with the same height and weight have the same BMI and fall into the same category.
That said, BMI means slightly different things in different bodies:
- Women on average carry more body fat than men at the same BMI.
- Older adults lose muscle with age, so a "normal" BMI can still hide extra fat.
- Athletes and people who lift weights can show as overweight because muscle is heavy.
- Pregnancy makes BMI meaningless for that period; doctors use pre-pregnancy BMI for guidance.
Some calculators ask for age and gender, but for adults the result is the same; those inputs are used for other estimates such as body fat percentage.
BMI for kids and teenagers
For children and teens, the formula is the same, but the number is compared with growth charts for their exact age and sex, because healthy BMI changes as children grow. The result is a percentile, not a fixed category.
In India, paediatricians commonly use the Indian Academy of Pediatrics growth charts; WHO also publishes BMI-for-age charts. Our BMI calculator does not do percentiles, so for a child, calculate the BMI number and ask a paediatrician to read it against the chart. The age calculator gives the child's exact age in years and months, which is what growth charts need.
Why BMI is not the whole picture
BMI is popular because it is free, fast and needs only a scale and a tape. But it cannot tell muscle from fat or show where the fat sits. Fat around the waist carries more health risk than fat on the hips.
Doctors often add:
- Waist circumference. Indian guidelines commonly flag a waist above about 90 cm for men and 80 cm for women.
- Blood pressure, blood sugar and cholesterol.
- Family history of diabetes or heart disease.
How to measure accurately
- Weigh yourself in the morning, after using the toilet and before eating, in light clothes.
- Measure height without shoes, standing straight against a wall, heels together.
- Use the same scale each time if you are tracking change.
To see progress as a percentage, for example going from 84 kg to 78 kg, use the % change row of the percentage calculator; our guide on percentage increase and decrease explains the formula.
Common mistakes
- Using feet as if they were metres. 5.6 is not 5 ft 6 in; 5 ft 6 in is 5.5 ft, or 1.676 m.
- Forgetting to square the height. Divide by height × height, not by height once.
- Using adult cut-offs for children. Kids need age-and-sex growth charts.
- Treating BMI as a diagnosis. It is a starting point for a conversation with a doctor.
Enter your weight and height in the BMI calculator for your number and healthy weight range, then compare it with the Indian cut-offs above.
Questions
How do I calculate BMI with weight in kg and height in feet?
Convert height to metres: (feet × 12 + inches) × 0.0254. Then divide weight in kg by height in metres squared. For 65 kg and 5 feet 6 inches (1.676 m), BMI is 65 ÷ 2.81 = 23.1.
What is a normal BMI for Indians?
Indian consensus guidelines treat about 18 to 22.9 as normal for adults, 23 to 24.9 as overweight and 25 or more as obese. These cut-offs are lower than the general WHO ones because Asian adults tend to have more health risk at the same BMI.
Is BMI different for men and women or by age?
For adults, the BMI formula and cut-offs are the same for men and women of any age. For children and teenagers, BMI is compared with growth charts for their age and sex, so the same number can mean different things at 8 and at 16.
Is BMI accurate?
It is a quick screening number, not a diagnosis. It does not separate muscle from fat or show where fat is stored. A doctor may also check waist size, blood pressure and blood tests.