BMI Calculator
BMI from your height and weight in cm and kg or feet, inches and lb, with the adult category and the weight range for a BMI of 18.5 to under 25. How it works
Use the BMI Calculator
About the BMI Calculator
An adult who is 175 cm tall and weighs 70 kg has a BMI of 22.85 (70 ÷ 1.75² = 22.857, shown rounded down), labeled Healthy Weight, the CDC’s name for that band. The BMI calculator places the figure on the CDC adult cut-offs, which apply from age 20, and shows the weight range that keeps a BMI of 18.5 to under 25 at your height. BMI is a screening measure, not a diagnosis.
CDC adult BMI categories
| BMI | Category |
|---|---|
| Under 18.5 | Underweight |
| 18.5 to under 25 | Healthy Weight |
| 25 to under 30 | Overweight |
| 30 to under 35 | Class 1 Obesity |
| 35 to under 40 | Class 2 Obesity |
| 40 or more | Class 3 Obesity (Severe) |
For adults 20 and older. The category is set on the unrounded BMI. Both the cut-offs and the names are the CDC’s, as the calculator prints them.
Weight range for BMI 18.5 to under 25, by height (metric)
| Height | Weight range |
|---|---|
| 150 cm | 41.7 to under 56.2 kg |
| 160 cm | 47.4 to under 64.0 kg |
| 170 cm | 53.5 to under 72.2 kg |
| 180 cm | 60.0 to under 81.0 kg |
| 190 cm | 66.8 to under 90.2 kg |
The lower limit is rounded up and the upper limit down to one decimal, as the calculator shows it, so every weight inside the range has a BMI of 18.5 to under 25.
Weight range for BMI 18.5 to under 25, by height (imperial)
| Height | Weight range |
|---|---|
| 5 ft 0 in | 94.8 to under 128.0 lb |
| 5 ft 4 in | 107.8 to under 145.6 lb |
| 5 ft 8 in | 121.7 to under 164.4 lb |
| 5 ft 10 in | 129.0 to under 174.2 lb |
| 6 ft 0 in | 136.5 to under 184.3 lb |
| 6 ft 4 in | 152.0 to under 205.3 lb |
The lower limit is rounded up and the upper limit down to one decimal, as the calculator shows it, so every weight inside the range has a BMI of 18.5 to under 25.
How to use this tool
- Choose metric (cm and kg) or imperial (feet, inches and lb) and enter your height and weight.
- Read the BMI, its category and the weight range for BMI 18.5 to under 25 at your height.
- For ages 2 to 19 use a BMI-for-age percentile tool instead.
Frequently asked questions
- What is a normal BMI for an adult?
- The CDC puts adults 20 and over with a BMI of 18.5 to under 25 in one band, which it calls Healthy Weight. 18.5 itself is in the band and 25 starts Overweight. For a 175 cm adult the range is 56.7 to under 76.5 kg.
- How do I calculate BMI in pounds and inches?
- Multiply the weight in pounds by 703 and divide by the height in inches squared. For 5 ft 10 in (70 in) and 150 lb that is 703 × 150 ÷ 4,900 = 21.52.
- Why is the BMI rounded down?
- The category is decided on the unrounded BMI and the figure is rounded down to two decimals, so the number never appears to sit in a different category from its label. At 170 cm, 72.2 kg is a BMI of 24.98, Healthy Weight, and 72.3 kg is 25.01, Overweight.
- Does the BMI calculator work for children and teens?
- No. These categories are for adults aged 20 and over. For ages 2 to 19 the CDC uses BMI-for-age percentiles, for example in its Child and Teen BMI Calculator.
- What is BMI prime?
- BMI prime is the BMI divided by 25, so 1.00 is the upper edge of the 18.5 to under 25 band. A 175 cm, 70 kg adult has a BMI of 22.85 and a BMI prime of 0.91.
- What do the obesity classes mean?
- The CDC splits BMI 30 or more into Class 1 (30 to under 35), Class 2 (35 to under 40) and Class 3 (40 or more), and calls Class 3 severe obesity; the calculator prints the same names. A 170 cm, 90 kg adult has a BMI of 31.14, which is Class 1 Obesity.
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