Athletes
BMI for athletes and muscular people
If you lift, play a sport or carry a lot of muscle, your BMI can say overweight when your body fat is low. Here is why, and what to check instead.
Short answer: BMI does not account for muscle. It only uses height and weight, so it cannot tell fat from muscle and bone. Athletes and other very muscular people can land in the overweight (25 to 29.9) or obesity (30 or more) category without having much body fat. The CDC says BMI should be considered together with other health measures. (CDC BMI FAQ; CDC About BMI)
Does BMI account for muscle?
- The CDC answers this directly: people with a lot of muscle might have a BMI in the overweight or obesity category, but "BMI cannot distinguish between fat, muscle, and bone mass." (CDC BMI FAQ)
- The NIH (NHLBI) says BMI "doesn't take into account your muscle mass, bone density, or body composition." (NHLBI Calculate Your BMI)
- The NHS says "if you have a lot of muscle, you may be classed as overweight or obese despite having low body fat." (NHS Calculate your BMI for adults)
The CDC, NIH and NHS do not give athletes a different BMI scale. They say to look at other measures as well.
Example: a muscular 5 ft 9 in athlete
| Height | Weight | BMI | Category by BMI alone |
|---|---|---|---|
| 5 ft 9 in | 160 lb | 23.6 | Healthy weight |
| 5 ft 9 in | 185 lb | 27.3 | Overweight |
| 5 ft 10 in | 200 lb | 28.7 | Overweight |
Calculated with the CDC formula: BMI = 703 × weight (lb) ÷ height (in)². For 5 ft 9 in (69 in) and 185 lb: 703 × 185 = 130,055, and 130,055 ÷ 69² (4,761) = 27.3. See how BMI is calculated.
A 5 ft 9 in rugby player or lifter at 185 lb has a BMI of 27.3, which BMI alone calls overweight. If most of that weight is muscle, the label is misleading. That is why the next two checks matter.
BMI vs body fat
- BMI is not a direct measure of body fat. For most people it is a good indicator, and it is "moderately to strongly associated" with direct body-fat measures. (CDC BMI FAQ; CDC About BMI)
- The precise way to measure body composition is a DEXA scan (dual-energy X-ray absorptiometry), but it is expensive and not widely available. (CDC About BMI)
- BMI also cannot show where fat is stored. (CDC BMI FAQ)
Better checks for muscular people
Waist-to-height ratio
The NHS says to try to keep your waist to less than half your height, and suggests using the waist-to-height check if your BMI is under 35. (NHS Overweight and obesity) Example: a 5 ft 9 in (69 in) athlete with a 32 in waist has a ratio of 32 ÷ 69 = 0.46, under half their height. See the full waist-to-height ratio chart.
Waist size
The NIH (NHLBI) says a waist of more than 35 inches for women or more than 40 inches for men increases risk of heart disease and type 2 diabetes when fat is mostly around the waist. Measure just above the hipbones, after breathing out. (NHLBI Healthy Weight)
Talk to a professional
For individuals, the CDC says to consider BMI together with blood pressure, cholesterol, a physical exam (including muscle mass) and lab results. (CDC About BMI)
Calculate BMI for athletes: BMI and waist-to-height
Enter your height, weight and waist to get your BMI and your waist-to-height ratio. For adults aged 20 and over. Nothing is sent or saved.
If your BMI is 25 or more but your waist is under half your height, the extra weight may be mostly muscle. A doctor can tell you for sure. Measure your waist just above the hipbones, after breathing out. More on the waist-to-height ratio chart. Prefer a plain BMI? Use the BMI calculator.
Questions
Is BMI accurate for athletes?
Not on its own. BMI cannot tell muscle from fat, so muscular athletes can read as overweight or obese without high body fat. The CDC says to consider other measures too.
What is a good BMI for an athlete?
There is no separate official BMI range for athletes; the adult categories are the same for everyone. For muscular people, waist-to-height ratio and waist size give a better picture.
Does BMI account for muscle?
No. It uses only height and weight.
Is BMI or body fat percentage better?
Body fat measured directly (for example with a DEXA scan) is more precise, but it is expensive and not widely available. BMI is a quick screening number.
I'm muscular and my BMI says obese. Should I worry?
Check your waist against your height. If you have questions about your weight or health, talk to a doctor; they can look at the whole picture.
More: BMI categories, BMI chart by height and weight and how BMI is calculated.
Sources
- CDC: BMI Frequently Asked Questions.
- CDC: About Body Mass Index (BMI).
- CDC: Adult BMI Categories.
- NIH (NHLBI): Calculate Your BMI.
- NIH (NHLBI): Healthy Weight (waist circumference).
- NHS: Overweight and obesity.
- NHS: Calculate your BMI for adults.
Last reviewed: 2026-10-09. Checked against the sources listed on this page.
BMI is a screening estimate, not a diagnosis and not medical advice. It does not measure body fat directly. For health questions, talk to a doctor or nurse.