from tkinter import Tk , ttk , messagebox
root=Tk()
root.title("BMI")

def buCalculate() :
   buCalculate = int(Weight.get()) / int(Height.get())**2
   messagebox.showinfo("Your BMI is : " , buCalculate)


ttk.Label(root,text= "Weight :").grid(row=0,column=0)
Weight=ttk.Entry(root,width=30,font=('Arial',20)).grid(row=0,column=3)

ttk.Label(root,text= "Height :").grid(row=1,column=0)
Height=ttk.Entry(root,width=30,font=('Arial',20)).grid(row=1,column=3)

buCalculate = ttk.Button(root,command=buCalculate,text="Calculate").grid(row=2,column=3)






root.mainloop()