BMI Calculator With Calculating How much Weight you must Loose or Gain

index(BMI).js

//Calculating the BMI

function BMI(weight , height){

    var calcBmi = (weight/(height**2));

    return  Math.floor(calcBmi*10)/10;
}

//Checking the Situation of the BMI

function situation(bmi) {
    if(bmi < 18.5){
       return "Under Weight";
    }
    if( bmi >= 18.5 && bmi <= 24.9){
        return "Normal Weight";
    }
    if( bmi >= 25 && bmi <= 29.9){
        return "Over Weight";
    }
    if( bmi >= 30 ){
        return "Obesity";
    }
}

//the Weight should be loss or gain

function toBeNormal(bmi1 , height1){
   

    if ( bmi1 < 18.5){
        var gainWeight = Math.floor ( ( 18.5 - bmi1 ) * 10 ) / 10;

            gainWeight = Math.floor ( ( gainWeight * ( height1 ** 2 )) * 10 ) / 10;

        return " | You must gain "+gainWeight+"Kg to be normal";
    }

    if ( bmi1 >= 18.5 && bmi1 <= 24.9){
        return " | Keep your body ;-)";
    }
    
    if ( bmi1 >= 25 ){
        var looseWeight = Math.floor ( ( bmi1 - 25 ) * 10 ) / 10;

            looseWeight = Math.floor ( ( looseWeight * ( height1 ** 2 )) * 10 ) / 10;

        return " | You must loose "+looseWeight+"Kg to be normal"
    }
}

//getting the data from user

var weight = prompt("Enter Your Weight in (KG)");
var height = prompt("Enter Your Height in (m2)");



var a = BMI ( weight , height );

//printing the data 

alert("Your BMI number is: "+ BMI( weight , height ) +" This means you are "+ situation(a) + toBeNormal( a , height ));