BMI calculator
Body Mass Index: your weight against your height, on the same scale the app uses.
Units
Your BMI
23.1
Normal
Weight (kg) ÷ height² (m)
1. What BMI measures
BMI is your weight in kilograms divided by the square of your height in metres. Two numbers you already know, one score you can compare over time.
Treat it as a screening number. It says where your weight sits for your height, and nothing about what that weight is made of.
2. The formula
- BMI
- weight (kg) ÷ height² (m)
A 75 kg lifter at 180 cm: 75 ÷ 1.80² = 23.1. The calculator rounds to one decimal, the same rounding the app applies before saving the result to your measurement log.
3. The four bands
| Category | BMI |
|---|---|
| Underweight | below 18.5 |
| Normal | 18.5 to 24.9 |
| Overweight | 25 to 29.9 |
| Obese | 30 and above |
The cut-offs are the WHO adult classification. The app colours your saved BMI on these same bands, so the result you read here matches the one in your log.
4. Where BMI falls short
BMI cannot tell muscle from fat. A 90 kg lifter at 180 cm scores 27.8 and lands in the overweight band while carrying less body fat than most people inside the normal one.
That blind spot is why the app pairs BMI with a body fat estimate. Read the two together: BMI for the long trend, body fat for what the weight is made of.
5. The same math in the app
BDYCTRL runs this exact calculation inside the measurement log, prefilled from your profile and saved against the day you logged it. Your BMI becomes a line over months instead of a number you look up once. Get the app.