## Java program to calculate BMI ( Body Mass Index ):

*BMI* or *body mass index* can be calculated by taking the *weight* in *pounds* and *height* in *inches* or by taking the *weight* in *kilograms* and *height* in *meters*. We have to use a different formula for both cases. In this example, we will learn how to do the calculation by using any of these *two* different approaches.

### BMI using weight in pound and height in inches :

The *BMI* for *pound/inches* is :

```
BMI = Weight(pound) * 730 /height (inches) * height (inches)
```

### BMI using weight in Kilogram and height in Meters :

The *BMI* for *Kilogram/Meters* is :

```
BMI = Weight(Kilogram)/height (Meters) * height (Meters)
```

We will also print if the result falls under *‘underweight’*, *‘normal’*, *‘overweight’* or *‘obese’*.

For that, let’s first calculate the BMI value and then check on which range it falls :

```
Less than 18.5 = Underweight
Between 18.5 to 24.9 = Normal
Between 25 to 29.9 = Overweight
30 or more than 30 = Obese
```

- In the program below, we have
*two*different methods to calculate the*BMI*by using the above methods. - For
*weight/height*in*pounds/inches*, ’*calculateBMImethodOne*’ will be called and for*weight/height*in kilogram/meters , ’*calculateBMImethodTwo*’ will be called. - We will ask the user either he wants to use approach
*1*or*2*. If he enters*1*, call the*first*method and for*2*, call method*2*. - Finally, pass the calculated BMI value to ’
*printBMIResult*’ method and print out a formatted string about the result. - You will get more clarification after going through the program :

### Java Program :

```
package com.company;
import java.util.Scanner;
public class Main {
/**
* Utility functions
*/
static void println(String string) {
System.out.println(string);
}
static void print(String string) {
System.out.print(string);
}
/**
* Print the final result
* @param bmi : calculated BMI result
*/
private static void printBMIResult(float bmi) {
String result = "";
if (bmi < 18.5) {
result = "underweight";
} else if (bmi < 25) {
result = "normal";
} else if (bmi < 30) {
result = "overweight";
} else {
result = "obese";
}
println("Your BMI is " + bmi + " and that means " + result);
}
/**
* calculate BMI if weight/height in pounds/inches
*/
private static void calculateBMImethodOne() {
Scanner scanner = new Scanner(System.in);
println("Enter weight in Pounds : ");
float weight = scanner.nextFloat();
println("Enter Height in inches : ");
float height = scanner.nextFloat();
float bmi = (weight * 703) / (height * height);
//print the result
printBMIResult(bmi);
}
/**
* calculate BMI if weight/height in kilogram/meters
*/
private static void calculateBMImethodTwo() {
Scanner scanner = new Scanner(System.in);
println("Enter weight in Kilogram : ");
float weight = scanner.nextFloat();
println("Enter Height in Meters : ");
float height = scanner.nextFloat();
float bmi = (weight) / (height * height);
//print the result
printBMIResult(bmi);
}
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
println("You can calculate BMI by entering weight in pounds and height in inches or Weight in Kilograms and Height in Meter.");
while (true) {
println("");
println("Enter 1 for entering weight/height in pounds/inches OR 2 for kilogram/meters : ");
int userInput;
userInput = sc.nextInt();
if (userInput == 1) {
calculateBMImethodOne();
break;
} else if (userInput == 2) {
calculateBMImethodTwo();
break;
} else {
println("Invalid Input !!!");
continue;
}
}
}
}
```

### Sample Example Output :

```
You can calculate BMI by entering weight in pounds and height in inches or Weight in Kilograms and Height in Meter.
Enter 1 for entering weight/height in pounds/inches OR 2 for kilogram/meters :
1
Enter weight in Pounds :
1234
Enter Height in inches :
23
Your BMI is 1639.8904 and that means obese
Enter 1 for entering weight/height in pounds/inches OR 2 for kilogram/meters :
2
Enter weight in Kilogram :
40
Enter Height in Meters :
6
Your BMI is 1.1111112 and that means underweight
Enter 1 for entering weight/height in pounds/inches OR 2 for kilogram/meters :
2
Enter weight in Kilogram :
60
Enter Height in Meters :
1.7
Your BMI is 20.761246 and that means normal
```