Your BMI, with honest context
A quick screen — useful, but not the whole story.
Results update as you type 🥑
How to read your BMI
BMI is your weight divided by height squared. It is a fast population-level screen for under- or over-weight, which is why clinicians use it as a first look.
But BMI does not know muscle from fat, where fat sits, or your age and ethnicity. A lean, muscular person can read “overweight”; someone at a “normal” BMI can still carry unhealthy visceral fat. Treat it as one data point.
For body composition, pair BMI with a body-fat estimate and a waist measurement. For energy goals, use your TDEE — BMI says nothing about how much to eat.
Common questions
Is BMI accurate?
It is accurate as a population screen, not as an individual body-composition measure. It cannot distinguish muscle from fat.
What is a healthy BMI?
For most adults, 18.5–24.9 is the “normal” range. Below 18.5 is underweight, 25–29.9 overweight, 30+ obese — context matters.
Why might a fit person have a high BMI?
Muscle is denser than fat. Athletes often read “overweight” despite low body fat — its main limitation.
Is my data stored?
No. Everything is calculated in your browser. Nothing is sent to a server or saved.
Sources & references
- Mifflin MD, St Jeor ST, et al. “A new predictive equation for resting energy expenditure in healthy individuals.” Am J Clin Nutr. 1990;51(2):241–247.
- Frankenfield D, Roth-Yousey L, Compher C. “Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults.” J Am Diet Assoc. 2005;105(5):775–789.
This calculator provides estimates for general educational use and is not medical advice. Consult a qualified professional before making significant dietary changes.