Body Mass Index — your weight in kilograms divided by the square of your height in metres. In imperial units it is 703 × pounds ÷ inches².

It's a useful screening tool for most people, but it can't distinguish muscle from fat. Treat it as one signal among several, not a diagnosis.

Your BMI divided by 25, the top of the healthy range. Under 0.74 is underweight, 0.74–1 is healthy, over 1 is overweight, over 1.2 is obese.

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BMI Calculator

Q: What counts as a healthy BMI?

The WHO's adult range is 18.5 to 25. Below 18.5 is underweight, 25–30 is overweight, and 30+ is obese (in three classes).

Q: Where does my data go?

Nowhere. Every number on this page is computed in your browser — no server, no database, no tracking.

Q: Why does the healthy range change for Asian adults?

At the same BMI, Asian adults tend to carry more body fat and face higher diabetes and heart-disease risk at lower BMIs. The WHO’s 2004 expert consultation set lower action points for Asian adults: overweight from 23, obese from 27.5.

Q: Why percentiles for children?

Children are still growing, so one fixed cut-off can’t fit every age. A BMI-for-age percentile shows where a child’s BMI stands among same-age, same-sex peers against the WHO growth standards (2-5y) and reference (5-19y); 5th-85th percentile counts as healthy.

Your body mass index — what it means, and a healthy weight range for your height. Computed entirely on your device; your numbers never leave this page.

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The calculator

What's your BMI?

BMI, BMR, daily calorie needs & body-fat — one free, private page.

Height (cm)

Weight (kg)

Enter your height and weight — results update as you type.

Height

Feet

Inches

Weight (lb)

Enter your height and weight — results update as you type.

Interpretation

Ethnicity

Age group

Your BMI

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Under Healthy Over Obese

Healthy weight range

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BMI Prime

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Distance to healthy

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Your estimated BMR

— kcal/day

Full calorie breakdown →

A quick note

This calculator gives general information only — it isn't medical advice. BMI can't tell muscle from fat, and it doesn't fit every body. If you have questions about your weight or health, talk to a qualified clinician.

Age

Sex

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Basal metabolic rate

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Mifflin-St Jeor equation

Daily energy expenditure

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10 × weight (kg) + 6.25 × height (cm) − 5 × age — plus 5 for men, minus 161 for women.

How active are you?

Daily calorie targets

Maintain weightEat at your TDEE

— kcal

Mild lossAbout 0.25 kg a week

— kcal

Lose weightAbout 0.5 kg a week — the standard safe rate

— kcal

Aggressive losscautionAbout 1 kg a week — hard to sustain

— kcal

Mild gainAbout 0.25 kg a week, mostly muscle with training

— kcal

Stay above the safe minimum unless a clinician supervises you — very low intakes need medical oversight.

Body-fat estimate

US Navy tape-measure method — waist, neck (and hips for women).

Waist (cm)

Neck (cm)

Hips (cm)

Estimated body fat

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Share this result

The link carries only your inputs — nothing else.

Questions, answered

What is BMI?

What counts as a healthy BMI?

Is BMI accurate?

Where does my data go?

What is BMI Prime?

Why does the healthy range change for Asian adults?

Why percentiles for children?

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