What is BMI?
Body Mass Index (BMI) is a simple number calculated from your height and weight that screens for weight categories associated with health risks. It's used by the WHO, doctors and researchers worldwide because it's fast, free and works reasonably well at the population level.
BMI formula
- Metric: BMI = weight (kg) ÷ height (m)²
- Imperial: BMI = 703 × weight (lb) ÷ height (in)²
What is BMI Prime?
BMI Prime is your BMI divided by 25 (the upper healthy limit). A value under 1.0 means you're within or below the healthy range; 1.1 means you're 10% above it. It makes it easy to see at a glance how far from the healthy boundary you are.
What is the Ponderal Index?
The Ponderal Index (kg/m³) divides weight by height cubed instead of squared. It corrects a known BMI weakness: BMI tends to overestimate for tall people and underestimate for short people. A typical healthy PI is roughly 11–15 kg/m³.
BMI chart (pounds and feet)
Find your height on the left and your weight across the top. Colours follow the WHO adult categories in the table above.
Underweight < 18.5 Healthy 18.5–24.9 Overweight 25–29.9 Obese 30+
| Height | 100 lb | 110 lb | 120 lb | 130 lb | 140 lb | 150 lb | 160 lb | 170 lb | 180 lb | 190 lb | 200 lb | 210 lb | 220 lb | 230 lb | 240 lb | 250 lb |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 4′ 10″ | 20.9 | 23.0 | 25.1 | 27.2 | 29.3 | 31.3 | 33.4 | 35.5 | 37.6 | 39.7 | 41.8 | 43.9 | 46.0 | 48.1 | 50.2 | 52.2 |
| 4′ 11″ | 20.2 | 22.2 | 24.2 | 26.3 | 28.3 | 30.3 | 32.3 | 34.3 | 36.4 | 38.4 | 40.4 | 42.4 | 44.4 | 46.5 | 48.5 | 50.5 |
| 5′ 0″ | 19.5 | 21.5 | 23.4 | 25.4 | 27.3 | 29.3 | 31.2 | 33.2 | 35.2 | 37.1 | 39.1 | 41.0 | 43.0 | 44.9 | 46.9 | 48.8 |
| 5′ 1″ | 18.9 | 20.8 | 22.7 | 24.6 | 26.5 | 28.3 | 30.2 | 32.1 | 34.0 | 35.9 | 37.8 | 39.7 | 41.6 | 43.5 | 45.3 | 47.2 |
| 5′ 2″ | 18.3 | 20.1 | 21.9 | 23.8 | 25.6 | 27.4 | 29.3 | 31.1 | 32.9 | 34.8 | 36.6 | 38.4 | 40.2 | 42.1 | 43.9 | 45.7 |
| 5′ 3″ | 17.7 | 19.5 | 21.3 | 23.0 | 24.8 | 26.6 | 28.3 | 30.1 | 31.9 | 33.7 | 35.4 | 37.2 | 39.0 | 40.7 | 42.5 | 44.3 |
| 5′ 4″ | 17.2 | 18.9 | 20.6 | 22.3 | 24.0 | 25.7 | 27.5 | 29.2 | 30.9 | 32.6 | 34.3 | 36.0 | 37.8 | 39.5 | 41.2 | 42.9 |
| 5′ 5″ | 16.6 | 18.3 | 20.0 | 21.6 | 23.3 | 25.0 | 26.6 | 28.3 | 30.0 | 31.6 | 33.3 | 34.9 | 36.6 | 38.3 | 39.9 | 41.6 |
| 5′ 6″ | 16.1 | 17.8 | 19.4 | 21.0 | 22.6 | 24.2 | 25.8 | 27.4 | 29.1 | 30.7 | 32.3 | 33.9 | 35.5 | 37.1 | 38.7 | 40.4 |
| 5′ 7″ | 15.7 | 17.2 | 18.8 | 20.4 | 21.9 | 23.5 | 25.1 | 26.6 | 28.2 | 29.8 | 31.3 | 32.9 | 34.5 | 36.0 | 37.6 | 39.2 |
| 5′ 8″ | 15.2 | 16.7 | 18.2 | 19.8 | 21.3 | 22.8 | 24.3 | 25.8 | 27.4 | 28.9 | 30.4 | 31.9 | 33.5 | 35.0 | 36.5 | 38.0 |
| 5′ 9″ | 14.8 | 16.2 | 17.7 | 19.2 | 20.7 | 22.2 | 23.6 | 25.1 | 26.6 | 28.1 | 29.5 | 31.0 | 32.5 | 34.0 | 35.4 | 36.9 |
| 5′ 10″ | 14.3 | 15.8 | 17.2 | 18.7 | 20.1 | 21.5 | 23.0 | 24.4 | 25.8 | 27.3 | 28.7 | 30.1 | 31.6 | 33.0 | 34.4 | 35.9 |
| 5′ 11″ | 13.9 | 15.3 | 16.7 | 18.1 | 19.5 | 20.9 | 22.3 | 23.7 | 25.1 | 26.5 | 27.9 | 29.3 | 30.7 | 32.1 | 33.5 | 34.9 |
| 6′ 0″ | 13.6 | 14.9 | 16.3 | 17.6 | 19.0 | 20.3 | 21.7 | 23.1 | 24.4 | 25.8 | 27.1 | 28.5 | 29.8 | 31.2 | 32.5 | 33.9 |
| 6′ 1″ | 13.2 | 14.5 | 15.8 | 17.2 | 18.5 | 19.8 | 21.1 | 22.4 | 23.7 | 25.1 | 26.4 | 27.7 | 29.0 | 30.3 | 31.7 | 33.0 |
| 6′ 2″ | 12.8 | 14.1 | 15.4 | 16.7 | 18.0 | 19.3 | 20.5 | 21.8 | 23.1 | 24.4 | 25.7 | 27.0 | 28.2 | 29.5 | 30.8 | 32.1 |
| 6′ 3″ | 12.5 | 13.7 | 15.0 | 16.2 | 17.5 | 18.7 | 20.0 | 21.2 | 22.5 | 23.7 | 25.0 | 26.2 | 27.5 | 28.7 | 30.0 | 31.2 |
| 6′ 4″ | 12.2 | 13.4 | 14.6 | 15.8 | 17.0 | 18.3 | 19.5 | 20.7 | 21.9 | 23.1 | 24.3 | 25.6 | 26.8 | 28.0 | 29.2 | 30.4 |
BMI chart (kilograms and centimetres)
| Height | 45 kg | 50 kg | 55 kg | 60 kg | 65 kg | 70 kg | 75 kg | 80 kg | 85 kg | 90 kg | 95 kg | 100 kg | 105 kg | 110 kg | 115 kg | 120 kg | 125 kg | 130 kg |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 150 cm | 20.0 | 22.2 | 24.4 | 26.7 | 28.9 | 31.1 | 33.3 | 35.6 | 37.8 | 40.0 | 42.2 | 44.4 | 46.7 | 48.9 | 51.1 | 53.3 | 55.6 | 57.8 |
| 155 cm | 18.7 | 20.8 | 22.9 | 25.0 | 27.1 | 29.1 | 31.2 | 33.3 | 35.4 | 37.5 | 39.5 | 41.6 | 43.7 | 45.8 | 47.9 | 49.9 | 52.0 | 54.1 |
| 160 cm | 17.6 | 19.5 | 21.5 | 23.4 | 25.4 | 27.3 | 29.3 | 31.2 | 33.2 | 35.2 | 37.1 | 39.1 | 41.0 | 43.0 | 44.9 | 46.9 | 48.8 | 50.8 |
| 165 cm | 16.5 | 18.4 | 20.2 | 22.0 | 23.9 | 25.7 | 27.5 | 29.4 | 31.2 | 33.1 | 34.9 | 36.7 | 38.6 | 40.4 | 42.2 | 44.1 | 45.9 | 47.8 |
| 170 cm | 15.6 | 17.3 | 19.0 | 20.8 | 22.5 | 24.2 | 26.0 | 27.7 | 29.4 | 31.1 | 32.9 | 34.6 | 36.3 | 38.1 | 39.8 | 41.5 | 43.3 | 45.0 |
| 175 cm | 14.7 | 16.3 | 18.0 | 19.6 | 21.2 | 22.9 | 24.5 | 26.1 | 27.8 | 29.4 | 31.0 | 32.7 | 34.3 | 35.9 | 37.6 | 39.2 | 40.8 | 42.4 |
| 180 cm | 13.9 | 15.4 | 17.0 | 18.5 | 20.1 | 21.6 | 23.1 | 24.7 | 26.2 | 27.8 | 29.3 | 30.9 | 32.4 | 34.0 | 35.5 | 37.0 | 38.6 | 40.1 |
| 185 cm | 13.1 | 14.6 | 16.1 | 17.5 | 19.0 | 20.5 | 21.9 | 23.4 | 24.8 | 26.3 | 27.8 | 29.2 | 30.7 | 32.1 | 33.6 | 35.1 | 36.5 | 38.0 |
| 190 cm | 12.5 | 13.9 | 15.2 | 16.6 | 18.0 | 19.4 | 20.8 | 22.2 | 23.5 | 24.9 | 26.3 | 27.7 | 29.1 | 30.5 | 31.9 | 33.2 | 34.6 | 36.0 |
| 195 cm | 11.8 | 13.1 | 14.5 | 15.8 | 17.1 | 18.4 | 19.7 | 21.0 | 22.4 | 23.7 | 25.0 | 26.3 | 27.6 | 28.9 | 30.2 | 31.6 | 32.9 | 34.2 |
BMI doesn't distinguish muscle from fat, so very muscular people can read as overweight. It's also not designed for children, whose BMI is judged against age-and-sex percentiles.
What is a healthy weight for my height?
One within a BMI of 18.5–24.9. At 5′4″ that's about 108–145 lb; at 5′10″, about 129–174 lb; at 6′0″, about 136–184 lb. Enter your height above and the calculator shows your exact range.
Is a BMI of 25 overweight?
Yes — 25.0 is where the WHO "overweight" band begins, and 30 is where obesity begins. For example, 180 lb at 5′9″ gives a BMI of 26.6. BMI is a screening figure, though, not a diagnosis.
What BMI is 200 pounds at 5′10″?
28.7 — in the overweight range. At 5′10″, the healthy range tops out around 174 lb.
Limitations of BMI
- Doesn't separate muscle from fat — athletes often read high while lean
- Doesn't show where fat is stored (belly fat is riskier)
- Adult thresholds don't apply to children, and may shift slightly for some ethnic groups
For a fuller picture, pair BMI with the body fat calculator and a waist measurement.
Is BMI accurate?
As a quick screen, yes — but it's one data point, not a diagnosis. Trends over time and body composition matter more than a single reading.
What BMI should I aim for?
Anywhere in the 18.5–24.9 healthy band. Within that band, the weight where you feel strong and energetic is the right one.
Does age or gender change BMI?
The formula is identical for adult men and women. Past ~65, slightly higher BMIs (up to ~27) are often considered acceptable.