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HEALTH

BMI Calculator

Estimate body mass index from weight, height with the BMI Calculator.

Choose an age groupAdult categories or an exact CDC 2000 BMI-for-age percentile.
2 options
BODY MASS INDEX24.5

Adult screening category: healthy-weight range. Educational estimate only; not medical advice.

Adult category
healthy-weight range
Estimate based on the values shown
MethodBMI from mass and height; pediatric percentiles use the official CDC 2000 monthly sex-specific LMS table with linear interpolation.

Before you use the result

Educational estimate only; it cannot diagnose a condition or replace advice from a qualified health professional.

Sources

EDITORIAL NOTES

Using the BMI Calculator responsibly

Page-specific guidance based on this calculator’s implemented method, inputs, and known limits.

What this result is useful for

BMI relates weight to height and is used as a population-level screening measure. This page supports adult BMI and, where selected, age- and sex-specific pediatric percentile calculations. A category is a screening signal, not a diagnosis or complete description of health.

Assumptions and limits

BMI does not directly measure body fat, fitness, bone density, pregnancy changes, or fat distribution. Adult cut points do not apply to children. Pediatric interpretation depends on accurate age, sex, height, and weight and uses the stated reference data.

How to check the result

Recheck units before interpreting the result: kilograms with metres squared, or the equivalent converted values. Unexpected results should be confirmed with a clinician who can consider growth history, body composition, medications, symptoms, and other relevant measurements.

Content review: August 30, 2026
CALCULATOR GUIDE

How to use the BMI Calculator

Estimate body mass index from weight, height with the BMI Calculator. It includes Adult BMI, Child and teen BMI workflows, so choose the one that matches the values you actually know. Use it to understand an educational estimate and the inputs behind it, not as a diagnosis or treatment decision.

Step by step

  1. For the BMI example, select Adult BMI and enter weight, height. Keep each value in the unit displayed beside its field.
  2. Review the selected BMI workflow and inputs, then read body mass index in the result panel.
  3. Change one BMI assumption at a time to compare scenarios. Use Reset to restore this tool's worked example values.

How the calculation works

BMI from mass and height; pediatric percentiles use the official CDC 2000 monthly sex-specific LMS table with linear interpolation.

Worked example

To reproduce the BMI worked example, reset the calculator. Select the Adult BMI workflow. Use weight 75 kg; height 175 cm. The result is body mass index of 24.5. Adult screening category: healthy-weight range. Review the displayed units before comparing the result.

Understanding the result

The BMI reports body mass index. Use it to understand an educational estimate and the inputs behind it, not as a diagnosis or treatment decision. Educational estimate only; it cannot diagnose a condition or replace advice from a qualified health professional.

How to check the answer

Check the BMI estimate by confirming the units and supported ranges for weight, height. Compare body mass index with another published method or direct measurement when available, and ask a clinician before using it for a health decision.

Common questions

What does the BMI calculate?

Estimate body mass index from weight, height with the BMI Calculator.

Which inputs does the BMI example use?

The worked example uses weight, height in the Adult BMI workflow. Other workflows can show different fields. Keep the chosen workflow and units with the result when comparing calculations.

Is the BMI result exact?

Educational estimate only; it cannot diagnose a condition or replace advice from a qualified health professional. Recheck weight, height and use body mass index only for a decision where that level of precision is appropriate.

Formula tests, limits, and sources reviewed September 1, 2026. Guide examples updated October 12, 2026.
INTERPRET THE RESULTRead the health guideCheck assumptions, limitations and comparison methods →
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