CDC adult screening category
For people age 20 and older, this calculator reports the fixed adult screening category shown in the table above. It does not diagnose an individual's health status. [1]
Educational reference only. Not a diagnostic tool. See full disclaimer.
General MedicineBMI
Adult BMI Calculator (Body Mass Index)
Calculate adult BMI from metric or US customary inputs, view the CDC adult screening category, and see the formula-derived weight span for BMI 18.5–24.9 at the entered height with non-diagnostic interpretation limits.
Content updated: View sources
QuickMedCalc is developed and maintained by an independent developer. Medical content is not independently reviewed by a physician.
Formula and medical content are based on the references listed on this page. See sources, About, and Sources and Review Process.
Input
kg
cm
These limits are calculator input-validation limits, not healthy or normal weight ranges.
Enter the height and weight values you intend to calculate. Small input differences may change the displayed category near a cutoff.
Adult BMI
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About
This calculator applies the adult BMI formula and reports the CDC adult screening category for people age 20 and older. BMI relates weight to height; it does not directly measure body fat, fat distribution, or organ function. It does not diagnose obesity, clinical obesity, preclinical obesity, or another disease, and it does not set a target weight or treatment plan. [1, 3, 5]
Ages 2–19 require pediatric BMI-for-age assessment rather than these fixed adult categories. Current pregnancy is outside the population addressed by the 2026 ADA adult obesity diagnosis framework used for context on this page. [2, 6]
Interpretation
| Displayed BMI | Adult screening category |
|---|---|
| < 18.5 | Underweight |
| 18.5–24.9 | Healthy weight |
| 25.0–29.9 | Overweight |
| 30.0–34.9 | Obesity, class 1 |
| 35.0–39.9 | Obesity, class 2 |
| ≥ 40.0 | Obesity, class 3 (severe obesity) |
The actual output is the CDC adult screening category for people age 20 and older. These category boundaries do not change by age, sex, or race, but they do not represent every current clinical guideline's diagnostic system. This page does not combine separate frameworks into a custom classification. [1]
How units and rounding are handled
Metric height is converted from centimeters to meters. US customary height is converted to total inches before applying the factor 703. [3]
This implementation keeps the raw result until the final display step, rounds BMI to one decimal place, and then assigns the CDC screening category from that displayed value.
The accepted height and weight limits are input-validation limits for this calculator, not healthy or normal ranges. [2]
Worked examples
Metric example
70 kg and 175 cm: 175 cm = 1.75 m.
70 ÷ 1.75² = 22.857… → displayed BMI 22.9 → Healthy weight
US customary examples
5 ft 9 in = 69 total inches.
703 × 168 ÷ 69² = 24.8066… → displayed BMI 24.8 → Healthy weight
703 × 169 ÷ 69² = 24.9542… → displayed BMI 25.0 → Overweight
The examples make the rounding boundary visible; a one-pound difference does not by itself establish a sudden diagnostic change. [1]
One BMI number, three different questions
ADA Standards of Care in Overweight and Obesity—2026
This standard applies to nonpregnant adults.
Non-Asian background
- Obesity: BMI ≥30 kg/m².
- Obesity: BMI 25–29.9 kg/m² with waist-to-height ratio (WHtR) ≥0.5.
- Obesity: BMI 25–29.9 kg/m² with waist circumference ≥88 cm for women or ≥102 cm for men.
- Overweight:
- BMI 25–29.9 kg/m² with WHtR <0.5; or
- BMI 25–29.9 kg/m² with waist circumference <88 cm for women or <102 cm for men.
Asian background
- Obesity: BMI ≥27.5 kg/m².
- Obesity: BMI 23–27.4 kg/m² with WHtR ≥0.5.
- Obesity: BMI 23–27.4 kg/m² with waist circumference ≥80 cm for women or ≥90 cm for men.
- Overweight:
- BMI 23–27.4 kg/m² with WHtR <0.5; or
- BMI 23–27.4 kg/m² with waist circumference <80 cm for women or <90 cm for men.
When examination suggests high muscle mass, the guideline recommends measuring waist circumference or body composition rather than diagnosing from BMI alone. This calculator does not collect background, waist circumference, the sex variable used by these criteria, or body composition. It therefore reports only the CDC screening category and does not produce an ADA diagnosis. [6]
2025 clinical-obesity framework
BMI is a screening measure. Excess adiposity usually requires confirmation by a direct measure or at least one other anthropometric measure; when BMI >40 kg/m², excess adiposity may be inferred. Clinical obesity also requires obesity-driven organ or tissue dysfunction or marked, age-adjusted limitation of daily activities. Preclinical obesity means confirmed excess adiposity with preserved organ function. This calculator cannot make either diagnosis. [5]
These frameworks answer different questions. This page presents them separately and does not combine them into a custom diagnostic rule.
Why some sources discuss Asian-background thresholds
A 2004 WHO consultation retained the international adult categories and identified additional public-health action points including BMI 23 and 27.5 kg/m² for Asian populations. ADA 2026 uses Asian-background-specific BMI and waist criteria in its adult obesity framework. This calculator still reports the CDC category and does not change its output based on identity. [4, 6]
When BMI can misclassify adiposity
- High muscle mass can raise BMI without the same degree of adiposity. [3, 6]
- Older age or low muscle mass can make BMI underestimate adiposity. [5]
- BMI does not show fat distribution; central adiposity can occur at a lower BMI. [3, 5]
- An error in entered height or weight changes the calculated BMI.
- Current pregnancy is outside the adult diagnostic standard discussed here. [6]
Which related measurement answers a different question?
- Waist-to-height ratio describes central fat distribution and is used by ADA in some BMI ranges. [6]
- Waist-to-hip ratio compares waist and hip circumference to describe a distribution pattern and is listed in the 2025 commission framework. [5]
- Relative fat mass is an estimate of whole-body fat percentage developed in a published study from waist circumference, height, and the published sex variable. It is not a direct body-composition measurement, and this page does not claim that it applies to every population or outperforms every method. [7]
References
- CDC. Adult BMI Categories.
- CDC. Adult BMI Calculator.
- CDC. BMI Frequently Asked Questions.
- WHO Expert Consultation. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet. 2004;363:157–163. PMID 14726171.
- Rubino F, et al. Definition and diagnostic criteria of clinical obesity. Lancet Diabetes Endocrinol. 2025;13:221–262. PMID 39824205.
- American Diabetes Association Professional Practice Committee for Obesity. Screening, Diagnosis, Evaluation, and Staging of Obesity in Adults: Standards of Care in Overweight and Obesity—2026. doi:10.2337/doci26-0003.
- Woolcott OO, Bergman RN. Relative fat mass as a new estimator of whole-body fat percentage. Scientific Reports. 2018;8:10980. PMID 30030479.
Related Calculators
WHtR
Calculate WHtR from waist circumference and standing height in centimeters, total inches, or feet/inches, with NICE applicability and measurement limits.
WHR
Calculate adult waist-to-hip ratio from standardized waist and hip circumferences in metric or US units.
RFM
Estimate adult whole-body fat percentage from height and waist circumference using the published Woolcott–Bergman RFM equation.
Disclaimer
Educational and informational reference only. Not intended to replace professional medical advice, diagnosis, treatment, or independent verification.