UNDERSTAND THE METHOD
How to use this calculator
Select adults or children and teens. Enter weight and standing height. For a child or teen, also enter the source sex category and completed age in years and additional months. The calculation adds half a month to the completed month. Adult results use fixed BMI categories; child results use the CDC age-specific reference.
What the result can tell you
BMI is a screening measure and is not a diagnosis or a direct body-fat measurement. Children need age-specific references. The CDC reference here covers 24 to less than 240 months. Children younger than 2 need WHO growth standards. The chart version and age assumption stay with the result.
Adult BMI categories and healthy weight by height
BMI is weight in kilograms divided by height in meters squared. For adults aged 20 and older, CDC uses the same categories for everyone. The calculator places an adult result in the category below.
CDC adult BMI categories
| Category | BMI (kg/m²) |
|---|---|
| Underweight | Below 18.5 |
| Healthy weight | 18.5 to below 25 |
| Overweight | 25 to below 30 |
| Obesity · class 1 | 30 to below 35 |
| Obesity · class 2 | 35 to below 40 |
| Obesity · class 3 | 40 and above |
The next table turns the healthy-weight category (BMI 18.5 to below 25) into body weight for common adult heights in feet and inches. Weights are rounded inward, so both ends of each range sit inside the category at that exact height.
Healthy-weight range by height, adults
| Height | Weight (lb) | Weight (kg) |
|---|---|---|
| 4 ft 10 in | 89 to 119 lb | 40.2 to 54.2 kg |
| 5 ft 0 in | 95 to 128 lb | 43.0 to 58.0 kg |
| 5 ft 2 in | 102 to 136 lb | 45.9 to 61.9 kg |
| 5 ft 4 in | 108 to 145 lb | 48.9 to 66.0 kg |
| 5 ft 6 in | 115 to 154 lb | 52.0 to 70.2 kg |
| 5 ft 8 in | 122 to 164 lb | 55.2 to 74.5 kg |
| 5 ft 10 in | 129 to 174 lb | 58.5 to 79.0 kg |
| 6 ft 0 in | 137 to 184 lb | 61.9 to 83.6 kg |
| 6 ft 2 in | 145 to 194 lb | 65.4 to 88.3 kg |
| 6 ft 4 in | 152 to 205 lb | 69.0 to 93.1 kg |
BMI is a screening measure, not a diagnosis, and CDC advises reading it alongside other health factors. Children and teens need age- and sex-specific percentiles instead of these adult cut points; choose the child or teen option above.
Common questions
How do I enter a child or teen age?
Enter completed years and additional completed months. The calculator adds half a month to that age to use the midpoint of the completed month.
Can I use the child reference for a child younger than 2?
No. This CDC reference covers 24 to less than 240 months. Children younger than 2 need the applicable WHO growth standards.
Sources & limitations4 sources
Sources checked September 12, 2026. These notes identify methods and assumptions. They have not received an independent clinical review.