⚖️ BMI Calculator
Enter your height and weight in US or metric units to get your BMI, weight category and the healthy weight range for your height. For adults 20+.
BMI chart for adults (WHO / CDC categories · your category is highlighted)
| Category | BMI (kg/m²) |
|---|---|
| Underweight | Below 18.5 |
| Healthy weight | 18.5 – 24.9 |
| Overweight | 25 – 29.9 |
| Obesity (class 1) | 30 – 34.9 |
| Obesity (class 2) | 35 – 39.9 |
| Obesity (class 3, severe) | 40 and above |
Healthy weight by height (BMI 18.5–24.9)
| Height | Healthy weight | Overweight from (BMI 25) | Obesity from (BMI 30) |
|---|---|---|---|
| 4′ 10″ (147 cm) | 89 – 119 lb | 120 lb | 144 lb |
| 5′ 0″ (152 cm) | 95 – 127 lb | 128 lb | 154 lb |
| 5′ 2″ (157 cm) | 101 – 136 lb | 137 lb | 164 lb |
| 5′ 4″ (163 cm) | 108 – 145 lb | 146 lb | 175 lb |
| 5′ 6″ (168 cm) | 115 – 154 lb | 155 lb | 186 lb |
| 5′ 8″ (173 cm) | 122 – 164 lb | 164 lb | 197 lb |
| 5′ 10″ (178 cm) | 129 – 174 lb | 174 lb | 209 lb |
| 6′ 0″ (183 cm) | 136 – 184 lb | 184 lb | 221 lb |
| 6′ 2″ (188 cm) | 144 – 194 lb | 195 lb | 234 lb |
| 6′ 4″ (193 cm) | 152 – 205 lb | 205 lb | 246 lb |
How to use the BMI calculator
Pick US units (feet, inches, pounds) or metric (centimeters, kilograms), enter your height and weight, and your BMI, weight category and the healthy weight range for your height appear instantly. Switching units converts the numbers you already typed. Add your waist circumference to also check abdominal-fat risk — sex is used only for that waist threshold and does not change the BMI itself.
What is BMI?
Body mass index (BMI) is your weight divided by the square of your height. It is a quick screening number that tells you whether your weight is in a typical range for your height. Doctors, the CDC and the World Health Organization (WHO) use it as a first-pass screen for underweight, overweight and obesity in adults because it needs no equipment — but it is a screening tool, not a diagnosis.
BMI formula
BMI = weight (kg) ÷ height (m)² or, in US units, BMI = 703 × weight (lb) ÷ height (in)²
Example: 5′9″ (69 inches) and 165 lb → 703 × 165 ÷ 69² = 115,995 ÷ 4,761 = 24.4, which is in the healthy range. To find the healthy weight range for a height, run the formula backwards: weight = BMI × height². At 5′9″, BMI 18.5 to 24.9 works out to about 125 to 168 lb. (The factor 703 converts lb/in² to kg/m²; this calculator uses the exact conversion, so results can differ from the 703 shortcut in the second decimal.)
BMI categories (WHO and CDC)
- Below 18.5 — underweight
- 18.5 to 24.9 — healthy weight
- 25 to 29.9 — overweight
- 30 and above — obesity, split into class 1 (30–34.9), class 2 (35–39.9) and class 3 (40+, sometimes called severe obesity)
Why Asian BMI cutoffs are lower
Research shows that many people of Asian descent carry more body fat and develop type 2 diabetes and heart disease at a lower BMI. For that reason the WHO Asia-Pacific guidance (and national guidelines in Korea, Japan and elsewhere) treat 23 or higher as overweight / at risk and 25 or higher as obese. The calculator shows that reading as a reference line. Some US clinics also use a lower threshold (BMI 23) for diabetes screening in Asian Americans.
Check your waist, too
BMI cannot tell muscle from fat or show where fat is stored. Fat around the belly is linked to higher risk of diabetes and heart disease even at a normal BMI. The NIH and CDC flag a waist circumference above 40 inches (102 cm) for men and 35 inches (88 cm) for women who are not pregnant. Measure just above your hip bones, after breathing out normally, with the tape snug but not pressing into the skin.
When BMI can be misleading
- Very muscular people — athletes and lifters often score "overweight" with low body fat.
- Older adults — muscle loss can hide extra body fat behind a normal BMI.
- Pregnancy — weight gain during pregnancy is not judged by BMI.
- Children and teens (ages 2–19) — use BMI-for-age percentiles from CDC growth charts instead of adult cutoffs. This calculator is for adults 20 and older.
This calculator applies the WHO/CDC adult BMI categories for general information only. It is not medical advice or a diagnosis — talk to a healthcare provider about your weight and health.