How is BMI calculated?

BMI = weight(kg) ÷ height²(m). Example: 70 kg, 1.75 m → 70 ÷ 3.0625 = 22.9 (normal weight). Our calculator does this instantly.

What is a normal BMI range?

WHO defines: Below 18.5 = underweight, 18.5–24.9 = normal, 25–29.9 = overweight, 30+ = obese. These thresholds apply to adults 18 and older.

Is BMI accurate for athletes and muscular people?

No. BMI cannot distinguish muscle from fat. A muscular athlete may score "overweight" while having very low body fat. For a complete picture, combine BMI with waist circumference and body fat percentage.

How often should I check my BMI?

For healthy adults, once every 3–6 months is sufficient. If actively managing your weight, monthly checks are appropriate. Always track alongside other health metrics.

Is this BMI calculator free to use?

Yes, completely free. No registration, no download, and no hidden fees. Works on all devices — desktop, phone, and tablet.

BMI berekenen — Direct Resultaat · WHO-Norm

De BMI-calculator berekent onmiddellijk uw Body Mass Index op basis van gewicht en lengte. De BMI is de door de WHO aanbevolen standaardmaatstaf voor gewichtsclassificatie: onder 18,5 is ondergewicht, 18,5 tot 24,9 normaal gewicht, 25 tot 29,9 overgewicht en 30 of meer obesitas. De formule is: BMI = gewicht (kg) gedeeld door lengte (m) in het kwadraat.

Een volwassene van 75 kg en 1,80 m heeft een BMI van 23,1, dus normaal gewicht. De BMI maakt geen onderscheid tussen spiermassa en lichaamsvet — een gespierde atleet kan als overgewicht worden geclassificeerd terwijl het vetpercentage laag is. Voor kinderen en adolescenten worden leeftijdsspecifieke percentielen gebruikt in plaats van vaste waarden. Combineer de BMI met de tailleomtrek en onze Caloriecalculator voor een volledig gezondheidsprofiel. Gratis, zonder registratie.

What is BMI and how is it calculated?

Body Mass Index is calculated by dividing your weight in kilograms by the square of your height in metres: BMI = kg ÷ m². The WHO defines four categories: Underweight (below 18.5), Normal (18.5–24.9), Overweight (25–29.9) and Obese (30 and above). The formula was developed by Belgian mathematician Adolphe Quetelet in 1832 and remains the most widely used population-level screening tool endorsed by the World Health Organization, the NHS and the CDC. For children and teenagers, age- and sex-specific percentile charts are used instead of adult thresholds.

Why BMI alone is not enough

BMI does not distinguish between fat mass and lean muscle mass, which means a muscular athlete may register as "overweight" while a sedentary person with excess visceral fat may score in the "normal" range. For a more complete picture, doctors combine BMI with waist circumference (risk increases above 88 cm for women and 102 cm for men), body fat percentage, and blood markers such as fasting glucose and cholesterol. Use our Calorie Calculator alongside your BMI result to understand your true energy needs, and our Water Intake Calculator to support your metabolism effectively.

BMI berekenen

What is BMI and how is it calculated?

Why BMI alone is not enough

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