How is BMI calculated?

BMI = weight (kg) ÷ height (m)². For imperial: weight in lb and height in inches use the standard conversion formula.

What is a healthy BMI?

WHO guidelines: Underweight below 18.5, Normal 18.5–24.9, Overweight 25–29.9, Obese 30 and above. Ranges may vary by population.

Is BMI accurate for everyone?

BMI is a population-level screening tool. It may misclassify very muscular people as overweight and may not suit children, elderly, or pregnant women without adjusted charts.

Can I use kg and feet together?

Switch between full Metric (kg, cm) or full Imperial (lb, ft/in) modes — mixed units are not supported to avoid errors.

Is my health data uploaded?

No. BMI is calculated entirely in your browser.

Everyday

BMI Calculator

Calculate Body Mass Index in kg/cm or lb/ft — see your BMI category and healthy weight range instantly.

100% client-side — your data never leaves this tab

Weight (kg)Height (cm)

BMI result

Your BMI

22.9

Normal weight

Healthy weight range for your height

56.7 – 76.3 kg

BMI is a screening tool, not a medical diagnosis. Consult a doctor for health advice.

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What is BMI Calculator?

BMI Calculator computes your Body Mass Index from height and weight — metric (kg and cm) or imperial (lb and ft/in). See your BMI value, category (underweight, normal, overweight, obese), and healthy weight range for your height. Free, instant, and private. Note: BMI is a screening tool, not a medical diagnosis.

BMI calculations run entirely in-browser; your measurements are never uploaded.

How to use BMI Calculator

1Choose Metric or Imperial units.
2Enter your weight and height.
3Read your BMI score and category.
4Check the healthy weight range suggested for your height.

Examples

Metric

70 kg, 175 cm → BMI 22.9 (Normal weight)

Imperial

154 lb, 5 ft 9 in → BMI ~22.7 (Normal weight)

Tips & common mistakes

BMI does not distinguish muscle from fat — athletes may show high BMI with low body fat.
Use the healthy weight range as a general guide, not a strict target.
Consult a doctor for personalized health advice, especially for children and elderly.
Track trends over time rather than a single reading.

Who uses this tool?

Adults checking BMI for general fitness awareness.
Students learning BMI formula in health education classes.
Fitness beginners setting a baseline before a health program.
Anyone needing a quick BMI check before a form or insurance questionnaire.

Frequently asked questions

How is BMI calculated?: BMI = weight (kg) ÷ height (m)². For imperial: weight in lb and height in inches use the standard conversion formula.
What is a healthy BMI?: WHO guidelines: Underweight below 18.5, Normal 18.5–24.9, Overweight 25–29.9, Obese 30 and above. Ranges may vary by population.
Is BMI accurate for everyone?: BMI is a population-level screening tool. It may misclassify very muscular people as overweight and may not suit children, elderly, or pregnant women without adjusted charts.
Can I use kg and feet together?: Switch between full Metric (kg, cm) or full Imperial (lb, ft/in) modes — mixed units are not supported to avoid errors.
Is my health data uploaded?: No. BMI is calculated entirely in your browser.