BMI Calculator
BMI is your weight divided by the square of your height. It is a quick screening number for whether your weight sits in a healthy range for your height — not a measure of body fat or health on its own.
- Accurate
- Real-time
- Easy to use
- 100% free
Body mass index
22.9
Healthy range (high)
76.3 kg
Details
Updates as you typeSummary
Healthy weightBody mass index
22.9
- Healthy range (low)
- 56.7 kg
- Healthy range (high)
- 76.3 kg
- Difference from healthy
- 0.0 kg
- BMI is a population-level screening tool. It does not distinguish muscle from fat, so athletes often read high and older adults often read low.
How this is calculated
- Weight
- 70.0 kg
- Height
- 1.75 m
- Height squared
- 3.063 m²
- BMI = weight ÷ height²
- 22.9
Compare scenarios
See how one change moves the result
- CurrentYour inputs as they stand22.9Current
- Weightkg 87.528.6
- Heightcm 21914.6
For informational purposes only. This is not medical advice — consult a healthcare professional about your health.
Frequently asked questions
What is a healthy BMI?
For most adults, 18.5 to 24.9 is classed as a healthy weight. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is obese. These thresholds apply to adults aged 20 and over.
Is BMI accurate?
It is accurate as a population screening tool and poor as an individual diagnosis. BMI cannot tell muscle from fat, so muscular athletes frequently score as overweight while people with low muscle mass can score healthy despite high body fat.
Does BMI differ for men and women?
The thresholds are the same for both. Women typically carry more body fat than men at the same BMI, which is one of the reasons BMI is best paired with a waist measurement.
What should I measure alongside BMI?
Waist circumference is the most useful companion measure, because abdominal fat carries the clearest health risk. A waist over 94cm (37in) for men or 80cm (31.5in) for women suggests increased risk regardless of BMI.