Enter your height and weight to instantly calculate your BMI, see your weight category, and get your healthy weight range.
If you've researched BMI before, you may have seen "24 = overweight, 27 = mildly obese, 30 = moderately obese" in one place, and "25 = overweight, 30 = obese" somewhere else. Both are correct — they're just different classification systems. This calculator's code uses cutoffs of 18.5 / 24 / 27 / 30 / 35, which is the Asia-Pacific BMI classification published by the WHO Western Pacific Region and used by health authorities across Taiwan, Japan, and Singapore. The more commonly cited international system is the WHO global standard, with cutoffs at 18.5 / 25 / 30 / 35, intended for the general worldwide population. That means the same BMI value — say, 24.5 — is already "overweight" under the Asia-Pacific standard, but still counts as "healthy weight" under the WHO global standard. Neither is wrong; research has shown East Asian populations tend to face elevated metabolic-disease risk at lower BMI values than other populations, which is why the lower Asia-Pacific thresholds are used regionally. That's also why the result on this page is explicitly labeled "(Asia-Pacific BMI classification)".
The BMI formula only uses two numbers — weight in kilograms divided by height in meters squared — and completely ignores muscle mass, bone density, body fat percentage, age, or sex. That means two people with an identical BMI can have very different body compositions: someone with years of strength training may land in the "overweight" category despite having low body fat and excellent metabolic health, while someone sedentary with low muscle mass might sit in the "healthy" range while carrying a high body fat percentage (sometimes called "skinny fat"). BMI works well as a quick screening tool across large populations, or as a rough number to track your own trend over time — but it should never be treated as a final diagnosis of your health. For a more accurate picture of body composition, consider a body-fat measurement, a waist-circumference check, or a conversation with a doctor or dietitian.
Using the tool's default values — height 170 cm, weight 65 kg — first convert height to meters (170 ÷ 100 = 1.7 m), then square it (1.7 × 1.7 = 2.89), then divide weight by that number (65 ÷ 2.89 ≈ 22.5). A BMI of 22.5 falls between 18.5 and 24, so it's classified as "Healthy weight." If weight increased to 75 kg with everything else unchanged, BMI would become 75 ÷ 2.89 ≈ 26.0, landing between 24 and 27 — now classified as "Overweight." The "Healthy weight range" shown on the page works the same formula in reverse: multiplying 18.5 and 24 by the squared height (2.89) gives the kilogram range — for someone 170 cm tall, that works out to roughly 53.5–69.6 kg.
Since the result depends entirely on the two numbers you enter, measurement accuracy matters. For height, measure barefoot against a wall, standing straight. For weight, measure in the morning on an empty stomach without heavy clothing, for the most consistent result. Also worth noting: this classification is designed for adults. For anyone under 18, growth is still in progress, so pediatric growth-chart percentiles — not adult BMI categories — are the appropriate way to assess whether a child's weight is on track.
You've probably seen the WHO global standard (cutoffs at 18.5 / 25 / 30 / 35) elsewhere. This tool uses the Asia-Pacific standard (cutoffs at 18.5 / 24 / 27 / 30 / 35), which sets a stricter threshold. Both are legitimate, official classifications — they're just calibrated for different population groups.
Not necessarily. BMI only looks at height and weight, so it can't distinguish muscle from fat. People with high muscle mass often land in the "overweight" or even "mildly obese" category despite having a healthy body fat percentage. In that case, a body-fat measurement or a trainer's assessment is more useful than the BMI number alone.
It works backward from your entered height: it finds the kilogram values where BMI equals 18.5 and 24 (your height in meters, squared, multiplied by each cutoff). That's the Asia-Pacific definition of a "healthy weight" for your height — change your height, and the range shifts accordingly.
It's not recommended. This classification is built for adults. Since bodies change substantially during growth, anyone under 18 should be assessed using pediatric growth-chart percentiles instead of adult BMI categories.
No. As soon as you type numbers into the height and weight fields, the result updates automatically — there's no submit or calculate button. If a field is empty or the value is zero or below, the result section stays hidden.