Ratio. It has a true zero.
ratio
"A BMI scale is used to calculate BMI or Body Mass Index; additionally, a BMI chart, formula, or a standard BMI calculator may be used to calculate BMI or Body Mass Index as well."
BMI = Mass : (Height)2 where mass is in kilograms and height is in metres.
nominal
Many sites sell scales that measure more than just your weight. To find a great bmi scale try visitng http://www.nextag.com/bmi-scale/stores-html or http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dgarden&field-keywords=bmi+scale&x=0&y=0.
Websites such as Fit Bit, Live Strong, WebMD, and Sport Fitness Adviser offer an online BMI scale for men. A BMI scale helps a person figure out their correct body mas index according to their height and weight.
Bmi
The bmi scale is not an actual device that your doctor would have. It is a mathematical equation that takes into account a persons height an weight and determines where they fall on the body mass index.
A height weight scale bases your height and weight in order to get your bmi. your bmi tells your doctor if you are in the healthy weight range or if you need to lose
There are several good scales that provide bmi readings. The Eat Smart Precision Scale is highly recommended for those who watch their weight. This scale is available at Amazon for $54.00.
BMI
overweight
BMI or the Body Mass Index