Enter your height and weight to calculate your Body Mass Index. See your BMI classification, a visual scale showing where you land, and the ideal weight range for your height — in metric or imperial units.
Units:
Try:
Your BMI
—
—
BMI Scale (10 – 45)
1018.525303545
Underweight <18.5Normal 18.5–24.9Overweight 25–29.9Obese I 30–34.9Obese II+ ≥35
Healthy Weight Range
Ideal weight for your height—
Based on BMI 18.5 – 24.9—
How to use
Select your preferred unit system — Metric (kg/cm) or Imperial (lb/ft+in).
Enter your weight and height. Results update instantly.
Your BMI value and classification appear in the result box.
The colour-coded scale bar shows exactly where your BMI falls.
The healthy weight range section shows the ideal weight band for your height.
Frequently Asked Questions
What is a healthy BMI?
A BMI between 18.5 and 24.9 is considered normal/healthy for adults. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is obese.
Is BMI accurate for everyone?
BMI is a general screening tool but has limitations — it doesn't distinguish muscle from fat, and may be less accurate for athletes, the elderly, or people of Asian or Pacific Islander descent who have different risk thresholds.
What is the ideal weight for my height?
This calculator shows the weight range that gives a BMI between 18.5 and 24.9 for your height. That is the range generally considered healthy for adults.
How is BMI calculated?
BMI = weight (kg) ÷ height (m)². For example, a person weighing 70 kg and 1.75 m tall: BMI = 70 ÷ (1.75 × 1.75) = 70 ÷ 3.0625 ≈ 22.9.
Does BMI apply to children?
Children use BMI-for-age percentiles rather than fixed cutoffs, since healthy BMI varies with age and sex during growth.
Did you know?
The BMI formula was invented by Belgian mathematician Adolphe Quetelet in the 1830s — he called it the "Quetelet Index." The term "Body Mass Index" was coined by physiologist Ancel Keys in 1972.
Many health organisations use different BMI thresholds for people of Asian descent — overweight is defined as BMI ≥ 23 and obese as BMI ≥ 27.5, because Asian populations show increased health risks at lower BMIs.
Shaquille O'Neal (2.16 m, ~147 kg during his playing career) had a BMI of around 31.5 — technically obese — despite being one of the most elite athletes in history.