Body Mass Index (BMI) Calculator Documentation

SK0rnev
02 November, 2018

Introductionnever

This is a documentation for the BMI calculator: https://skkk1972.shinyapps.io/BMI2018/.

The BMI (Body Mass Index) is used by the medical profession to quickly and simply determine a person's weight in regard to their height. It is a measure that uses your height and weight to work out if your weight is healthy.

The BMI calculation divides an adult's weight in kilograms by their height in metres squared. For example, A BMI of 25 means 25kg/m2.

From a straight forward calculation the BMI factor can be gained and gives a measure which can be used to determine if a person is underweight, of normal weight, overweight or obese.

BMI ranges

World Health Organization divides BMI into the next grous

If your BMI is:

  • below 16 - you're in the “Severe Thinness” category
  • between 16 and 17 - you're in the “Moderate Thinness” range
  • between 17 and 18.5 - you're in the “Mild Thinness” range
  • between 18.5 and 25 - you're in the “Normal” range
  • between 25 and 30 - you're in the “Overweight” range
  • between 30 and 35 - you're in the “Obese Class I” range
  • between 35 and 40 - you're in the “Obese Class II” range
  • above 40 - you're in the “Obese Class III” range

BMI Calculator Manual with pictures

Fill in respective windows with your Height in centimetres and Weight in kilograms. Click “Submit” button

You can see your result (BMI and your group) at the bottom of the right pannel

Example

R code for Height=170cm and Weight=85kg 

h <- 170
w <- 85
BMI <-  w/(h/100)^2
BMI <- round(BMI,2)
if (BMI < 16) {category <- "Severe Thinness"}
if (BMI >=16 & BMI < 17) {category <- "Moderate Thinness"}
if (BMI >=17 & BMI < 18.5) {category <- "Mild Thinness"}
if (BMI >=18.5 & BMI < 25) {category <- "Normal"}
if (BMI >=25 & BMI < 30) {category <- "Overweight"}
if (BMI >=30 & BMI < 35) {category <- "Obese Class I"}
if (BMI >=35 & BMI < 40) {category <- "Obese Class II"}
if (BMI >=40) {category <- "Obese Class III"}
paste("Your BMI:", BMI, category)

[1] "Your BMI: 29.41 Overweight"