BMI Calculator

Calculate your Body Mass Index — with visual scale, category & healthy weight range

Height

100 cm220 cm

Weight

30 kg200 kg

Your BMI

—

BMI Scale

Underweight
<18.5

Normal
18.5–25

Overweight
25–30

Obese
30+

▲

Healthy weight for your height: —

BMI Categories Reference

Category	BMI Range	Health Risk
Underweight	< 18.5	Nutritional deficiency risk
Normal Weight	18.5 – 24.9	Low risk
Overweight	25.0 – 29.9	Moderate risk
Obese Class I	30.0 – 34.9	High risk
Obese Class II	35.0 – 39.9	Very high risk
Obese Class III	≥ 40.0	Extremely high risk

How to Use the BMI Calculator

Choose your unit system — Metric (kg/cm) or Imperial (lbs/ft in).
Set your height using the slider or type it directly.
Set your weight — the result updates instantly as you adjust.
Read your BMI on the scale — the arrow shows exactly where you fall.
Check your healthy weight range for your height shown below the scale.

BMI Limitations

Doesn't measure body fat
BMI can't distinguish between muscle and fat. Athletes may be classified as "overweight" despite being very healthy.

Age & sex variation
The same BMI can mean different things for men vs women, and for different age groups. Children use separate BMI-for-age charts.

Ethnicity differences
Some health organisations use lower BMI thresholds for certain ethnic groups due to differences in body composition.

Not a diagnosis
BMI is a screening tool, not a medical diagnosis. Always consult a healthcare professional for health advice.

Frequently Asked Questions

What is a healthy BMI?

For most adults, a BMI between 18.5 and 24.9 is considered healthy. However, optimal ranges can vary by age, sex, and ethnicity — consult your doctor for personalised guidance.

How is BMI calculated?

BMI = weight (kg) ÷ height² (m²). For example, 70 kg at 1.75 m gives a BMI of 70 ÷ (1.75 × 1.75) = 22.9, which is in the normal range.

Is BMI accurate for athletes?

Not always. Athletes with high muscle mass may have an elevated BMI while having low body fat. For a more accurate assessment, tools like DEXA scanning or body fat percentage measurement are preferred.

Does BMI apply to children?

No — children and teenagers use BMI-for-age percentile charts that account for growth and development. This calculator is designed for adults (age 18+).