What is the BMI Calculator?
Body mass index (BMI) is weight divided by height squared (kg/m²). It's a quick screening measure that places adults into weight categories. Cubestack calculates it in metric or imperial units.
How to use it
- 1
Choose units
Select metric or imperial.
- 2
Enter height and weight
Type your measurements.
- 3
Read your BMI
See your BMI and its category.
Features
Metric or imperial
Use kg and cm, or lb and inches.
Category
See whether your BMI falls in the underweight, normal, overweight or obese range.
Instant result
BMI updates as you type.
Private
Your measurements stay in your browser.
Popular uses
Health tracking
Monitor BMI as your weight changes.
Fitness goals
Set a target weight range for your height.
Quick checks
Calculate BMI for family members.
Frequently asked questions
What is a healthy BMI?
For adults, 18.5 to 24.9 is considered the healthy range by the WHO.
Is BMI accurate for athletes?
BMI doesn't distinguish muscle from fat, so muscular people can read as overweight. Consider waist measurement too.
Does BMI apply to children?
Children and teens use age- and sex-specific BMI percentiles rather than adult categories.
Is this medical advice?
No. BMI is a screening tool — talk to a doctor about your health.