The adult BMI chart
The World Health Organization classification below applies to adults aged 20 and over, men and women alike. The calculator on this page uses exactly these bands, shows where your value falls on the scale and gives the weight range that corresponds to a BMI of 18.5 to 24.9 at your height.
Underweight is sometimes split further: below 16 is severe thinness, 16 to 16.9 moderate and 17 to 18.4 mild thinness.
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 to 24.9 | Normal weight |
| 25.0 to 29.9 | Overweight (pre-obesity) |
| 30.0 to 34.9 | Obesity class I |
| 35.0 to 39.9 | Obesity class II |
| 40.0 and above | Obesity class III |
Try it here: BMI Calculator
Open the full tool pageHow BMI is calculated
Metric formula: BMI = weight in kg / (height in m × height in m). For someone 170 cm tall weighing 70 kg: 1.70 × 1.70 = 2.89, and 70 / 2.89 = 24.2, which is normal weight. At 180 cm and 90 kg: 90 / 3.24 = 27.8, overweight.
US formula: BMI = 703 × weight in pounds / (height in inches × height in inches). The factor 703 converts pounds and inches to the metric result. For 5 feet 9 inches (69 inches) and 160 pounds: 69 × 69 = 4,761, and 703 × 160 / 4,761 = 23.6.
The calculator has both unit systems: choose Metric (cm, kg) or US (ft, in, lb), type your height and weight, and the result updates as you type. It also shows BMI Prime, which is your BMI divided by 25, the upper limit of the normal range: 0.97 means you are 3 percent below that limit, 1.10 means 10 percent above it.
BMI chart by height
The table gives the weight range for a BMI of 18.5 to 24.9 at common heights, and the weight at which the overweight band ends (BMI 29.9). Read across your height to see which band your weight falls in.
| Height | Normal weight (BMI 18.5 to 24.9) | Overweight up to (BMI 29.9) |
|---|---|---|
| 150 cm (4 ft 11 in) | 41.6 to 56.0 kg (92 to 123 lb) | 67.3 kg (148 lb) |
| 155 cm (5 ft 1 in) | 44.4 to 59.8 kg (98 to 132 lb) | 71.8 kg (158 lb) |
| 160 cm (5 ft 3 in) | 47.4 to 63.7 kg (104 to 140 lb) | 76.5 kg (169 lb) |
| 165 cm (5 ft 5 in) | 50.4 to 67.8 kg (111 to 149 lb) | 81.4 kg (179 lb) |
| 170 cm (5 ft 7 in) | 53.5 to 72.0 kg (118 to 159 lb) | 86.4 kg (190 lb) |
| 175 cm (5 ft 9 in) | 56.7 to 76.3 kg (125 to 168 lb) | 91.6 kg (202 lb) |
| 180 cm (5 ft 11 in) | 59.9 to 80.7 kg (132 to 178 lb) | 96.9 kg (214 lb) |
| 185 cm (6 ft 1 in) | 63.3 to 85.2 kg (140 to 188 lb) | 102.3 kg (226 lb) |
| 190 cm (6 ft 3 in) | 66.8 to 89.9 kg (147 to 198 lb) | 107.9 kg (238 lb) |
What BMI does not tell you
BMI only knows height and weight. It cannot tell muscle from fat, so strength athletes and very muscular people often score as overweight or even obese while having little body fat. The opposite also happens: an older adult who has lost muscle can have a normal BMI and still carry too much fat, especially around the waist.
Where fat sits matters for health more than total weight. Waist circumference adds this information: the WHO links a waist above 94 cm (37 in) for men and 80 cm (31.5 in) for women with increased risk, and above 102 cm (40 in) and 88 cm (34.6 in) with substantially increased risk. A simple rule used by some health services is to keep your waist below half your height.
Ethnicity also shifts the risk at a given BMI. People of South Asian, Chinese and other Asian backgrounds tend to develop type 2 diabetes and heart disease at lower BMI values, so some health organizations use lower action points, around 23 for increased risk and 27.5 for high risk. BMI is also not meaningful during pregnancy, and in very tall or very short people it is less reliable.
- Muscular build: BMI may overstate body fat.
- Older age: BMI may understate body fat because muscle declines.
- Asian background: health risks start at lower BMI values.
- Pregnancy: BMI does not apply.
- Children and teenagers: adult categories do not apply.
BMI for children and teenagers
For anyone under 20 (under 19 in the WHO charts), the same formula is used but the result is compared with growth charts for the child's exact age and sex, because body fat changes a lot as children grow and differs between boys and girls. The result is a percentile, not a category from the adult table.
In the CDC charts used in the United States, below the 5th percentile counts as underweight, the 5th to below the 85th percentile as a healthy weight, the 85th to below the 95th as overweight and the 95th or above as obesity. The WHO growth references use similar cutoffs expressed in standard deviations. The calculator on this page is made for adults; for a child, ask a pediatrician or use an official growth chart.
Using BMI sensibly
BMI works best as a starting point and for following a trend over time. A change from 31 to 28 over a year says something real even if your build makes the absolute number imperfect. Measure at the same time of day, ideally in the morning, since weight can vary by 1 to 2 kg (2 to 4 lb) during a day.
If your BMI is outside the normal range, or inside it but your waist is large, a doctor can add blood pressure, blood tests and family history for a real assessment. This guide and the calculator give general information and are not medical advice.