B.M.I Calculator in java

main.java

import javax.swing.JOptionPane;

public class main {
	public static void main(String[] args) {
		// B.M.I = Mass (kg) / (Height (M))^2
		String Mass = JOptionPane.showInputDialog("Input your mass in kilograms");
		String Height = JOptionPane.showInputDialog("Input your height in Centimeters");
		double MassD = Double.valueOf(Mass);
		double HeightD = Double.valueOf(Height);
		HeightD = HeightD/100.0;
		double BMI = MassD / Math.pow(HeightD, 2);
		double MinNormalMass = 18.5 * Math.pow(HeightD, 2);
		double MaxNormalMass = 24.9 * Math.pow(HeightD, 2);
		boolean IsFat = MassD > MaxNormalMass;
		boolean IsSkinny = MassD < MinNormalMass;
		boolean IsFit = MassD >= MinNormalMass && MassD <= MaxNormalMass;
		Integer PerfectWeight = (int) Math.round((MaxNormalMass+MinNormalMass)/2);
		if(IsFat) {
			JOptionPane.showMessageDialog(null, "You're fat, Your weight shouldn't exceed "+Math.round(MaxNormalMass)+" Kilograms.\nPerfect Weight is: "+PerfectWeight+" Kilograms.\n You should lose "+Math.round((MassD-MaxNormalMass))+" Kilograms.");
		}else if(IsSkinny) {
			JOptionPane.showMessageDialog(null, "You're skinny, Your weight should be "+Math.round(MinNormalMass)+" Kilograms.\nPerfect Weight is: "+PerfectWeight+" Kilograms.\n You should gain "+Math.round((MinNormalMass-MassD))+" Kilograms");
		}else if(IsFit) {
			JOptionPane.showMessageDialog(null, "You're fit !"+"\nPerfect Weight is: "+PerfectWeight);
		}
		}
}