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Rotina Diária

BMI Calculator

Calculate your body mass index and see the WHO classification and healthy weight range.

BMI is only one indicator.

It doesn’t distinguish muscle from fat and isn’t suitable for children and teens (who use age-based growth charts), pregnant people, or—without adjustments—older adults and athletes. It doesn’t replace an evaluation by a doctor or dietitian.

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How to use: BMI Calculator

  1. Enter your weight in kilograms.
  2. Enter your height in meters (1.75) or centimeters (175).
  3. See your BMI, classification, and the weight range considered normal for your height.

About this tool

BMI is your weight divided by your height squared (kg/m²). According to the World Health Organization classification for adults: below 18.5 is underweight; 18.5 to 24.9 is normal weight; 25 to 29.9 is overweight; and 30 or higher is obesity (Classes I, II, and III).

BMI is a simple population-level screening measure with limitations: it doesn’t distinguish muscle from fat or account for fat distribution (waist circumference can provide additional insight). Children and teens use age- and sex-specific growth charts. Talk to a healthcare professional for a full assessment.

Frequently asked questions

What is an ideal BMI?

For adults, the WHO defines a normal BMI as 18.5 to 24.9. BMI ranges may differ for older adults, so consult a healthcare professional for guidance.

Is BMI accurate for athletes and muscular people?

Not always. Muscle weighs more than fat, so athletes may have a BMI in the overweight range while still being healthy. Body composition measurements may be more useful in these cases.

How do you calculate BMI by hand?

Divide your weight by your height squared. Example: 70 kg ÷ (1.75 × 1.75) = 70 ÷ 3.0625 = 22.9.

Is it really free? Is there a daily limit?

It's free with no daily limits. Processing happens on your device, so there's no per-use cost and no need to limit you.

Does it work on phones?

Yes. The site works in any modern browser on Android, iPhone, Windows, Mac, and Linux—no installation needed.

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