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General Health & Preventive Medicine CDC adult BMI category screening tool Activated — adult screening estimate Routine educational estimate

Adult BMI Calculator

Calculate adult body mass index and CDC BMI category from height and weight, with healthy-weight range estimates.

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Interactive tool

Calculator

Enter values carefully. Results appear after calculation and should be interpreted with the safety notes and source method on this page.

Activated — adult screening estimate

Step 1 — Enter inputs

5 fields required for this tool

Step 2 — Review the result

The result area updates below and keeps safety wording visible.

Result

Complete the form and select Calculate.

About this calculator

This adult BMI calculator estimates body mass index from height and weight and places the result into CDC adult BMI categories. It also shows an estimated weight range associated with the healthy BMI interval for the entered height.

BMI is a screening measure, not a diagnosis. It does not directly measure body fat, muscle mass, pregnancy status, ethnicity-specific risk, or cardiometabolic health.

Source-backed
Uses the standard BMI formula, BMI = weight in kilograms divided by height in meters squared, and CDC adult BMI categories for adults 20 years and older.
Review status
Activated — adult screening estimate
Limitations
Educational estimate only; not a diagnosis, prescription, or treatment plan.

Formula and method

BMI = weight in kilograms ÷ height in meters². Adult category cutoffs used here: underweight below 18.5, healthy weight 18.5 to less than 25, overweight 25 to less than 30, and obesity 30 or higher, with obesity classes shown when applicable.

Medical safety note: This page is for education only and should not replace professional medical advice. For emergencies, medication decisions, or severe symptoms, contact a qualified clinician or local emergency service.

Limitations and when not to rely on this result

  • Educational estimate only; not a diagnosis, prescription, or treatment plan.
  • Result depends on accurate inputs and may not apply to complex medical situations.
  • Use clinician judgment, local guidance, and urgent care pathways when symptoms are severe.

Frequently asked questions

Is BMI a diagnosis? +

No. BMI is a screening measure. It can help flag weight categories associated with health risk, but it does not diagnose body fatness, fitness, or disease.

Who is this adult BMI calculator for? +

It is intended for adults age 20 and older. Children and teens should use BMI-for-age percentile tools instead of adult BMI categories.

Why can BMI be misleading for athletes? +

BMI uses only height and weight. Very muscular people can have a high BMI without having high body fat.

Does pregnancy change BMI interpretation? +

Yes. BMI during pregnancy should not be interpreted like ordinary adult BMI. Use pre-pregnancy BMI for pregnancy weight-gain guidance.

What is the healthy adult BMI range? +

CDC adult categories define healthy weight as BMI 18.5 to less than 25 kg/m².