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Health Calculator

What Is BMI?

BMI (Body Mass Index) is a numerical value of your body weight in relation to your height. It is commonly used to classify whether a person is underweight, normal weight, overweight, or obese. BMI is the most widely used screening tool for assessing body weight health in adults worldwide.

⚖️ BMI Index

Check your body mass index

Your BMI 0
Category --
Underweight
<18.5
Normal
18.5-24.9
Overweight
25-29.9
Obese
≥30

🔥 BMR Rate

Calories you burn at complete rest

BMR 0
kcal/day at rest

🍽️ Daily Calories

Calories you need to maintain weight

Daily Calories 0
kcal/day to maintain weight
Lose 0.5kg/week -500 kcal
Lose 1kg/week -1000 kcal
Gain 0.5kg/week +500 kcal
Gain 1kg/week +1000 kcal

🎯 Ideal Weight

Target weight based on 4 medical formulas

Robinson 0 kg
Miller 0 kg
Devine 0 kg
Hamwi 0 kg
Average Ideal Weight 0 kg

BMI Categories

CategoryBMI Range
UnderweightBelow 18.5
Normal weight18.5 – 24.9
Overweight25 – 29.9
Obese30 and above

⚠️ Asian populations: Health risks begin at lower BMI levels in Asian adults. Consider BMI 23 as the overweight threshold (instead of 25) and BMI 27.5 as the obese threshold (instead of 30) if you are of Asian descent.

What BMI Cannot Tell You

BMI does not distinguish muscle from fat, and it ignores bone density, age, gender, and ethnicity. A bodybuilder may score as obese despite having very little body fat. Use BMI as a starting point — not a diagnosis. For a complete health picture, combine it with waist circumference, body fat percentage, and blood pressure readings.

Frequently Asked Questions

How is BMI calculated?

BMI = weight (kg) ÷ height² (m²). This calculator handles both metric and imperial units — just toggle your preferred system and enter your height and weight.

Is BMI calculated differently for women?

The formula is the same, but body composition differs. Women typically carry 6–8% more body fat than men at the same BMI. Some experts suggest slightly lower BMI cutoffs for women in clinical settings.

What's the difference between BMI for men and women?

The formula stays the same, but women on average have more body fat at identical BMI. No major health organization currently uses gender-specific BMI cutoffs for general screening, though research suggests different thresholds may be more accurate.

Why do Asian populations have different BMI cutoffs?

Studies show Asian populations develop metabolic risks like type 2 diabetes at lower BMI values. The WHO recommends BMI 23 as the overweight threshold and 27.5 as the obese threshold for Asian adults, lower than the standard 25 and 30.

What units does this calculator use?

Both. Toggle between metric (kg/cm) and imperial (lb/ft-in) — the result is the same BMI number regardless of which system you use.