What is a healthy BMI range?

A BMI between 18.5 and 24.9 is considered the normal or healthy weight range for adults. Below 18.5 is underweight, 25.0–29.9 is overweight, and 30 or above is classified as obese by standard medical definitions.

Is BMI accurate for everyone?

Not entirely. BMI doesn't account for muscle mass, bone density, age, or fat distribution. Athletes often register as overweight due to muscle mass, while some people with a 'normal' BMI may carry excess visceral fat. It's a useful population screening tool but not a personal health diagnosis.

How do I calculate BMI manually?

In metric: BMI = weight (kg) / height (m)². For example, 70 kg at 1.75 m gives 70 / (1.75 × 1.75) = 22.9. In imperial: BMI = (weight in lbs × 703) / height in inches².

Does BMI differ for children?

Yes. For children and teens aged 2–19, BMI is plotted on age- and sex-specific growth charts. The same number means different things at different ages. This calculator is designed for adults.

What is the ideal weight range for my height?

The ideal weight range is the weight span that corresponds to a BMI of 18.5–24.9 for your height. The calculator shows this range automatically in both kg and lbs once you enter your height.

BMI計算機

メートル法またはヤードポンド法でBMIを計算。BMIカテゴリと身長に適した理想体重範囲を即座に表示します。

単位系

体重

身長

体重と身長を入力するとBMIが計算されます。

使い方

メートル法またはヤードポンド法でBMIを計算。BMIカテゴリと身長に適した理想体重範囲を即座に表示します。

1Select your preferred unit system — Metric (kg and cm) or Imperial (lbs and feet/inches) — using the toggle at the top.
2Enter your weight. In metric, type kilograms. In imperial, type pounds.
3Enter your height. In metric, type centimeters. In imperial, enter feet and inches separately in the two fields.
4Your BMI appears instantly with a color-coded result: blue for underweight, green for normal, amber for overweight, and red for obese.
5Check the BMI scale bar to see where your number falls visually, and the ideal weight section to see the healthy weight range for your height.

主な機能

Metric and imperial support — switch between kg/cm and lbs/ft-in with a single click
Color-coded BMI categories — instant visual feedback with blue/green/amber/red coding
Visual BMI scale bar — see exactly where your BMI falls on the full 10–40+ range
Ideal weight range — shows the healthy weight range for your height in both kg and lbs
Instant calculation — results update live as you type, no button required

よくある質問

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BMI Calculator — What Your Number Actually Means (And What It Doesn't)