Why isnt math mathing in this code | C++ | Page 1

Im making a BMI calculator and the formula is weight divided by height squared multipled by 703 but whenever i type in any number it gives me 0. Please help

#include <iostream>
#include <cmath>

int main()
{
    int pounds_lb;
    int height_in;
    double BMI = pounds_lb / pow(2, height_in) * 703;
    
    
    std::cout << "Welcome to the BMI CALCULATOR \n";
    std::cout << "Please enter your weight in POUNDS: ";
    std::cin >> pounds_lb;
    
    while(pounds_lb < 0){
        std::cout << "Please enter a positive number: ";
        std::cin >> pounds_lb;
    }

    std::cout << "Please enter your height in INCHES: ";
    std::cin >> height_in;
    
    while(height_in < 0){
        std::cout << "Please enter a positive number: ";
        std::cin >> height_in;
    }

    
    


    return 0;

}

#Why isnt math mathing in this code