C++ BMI Calculator Program: Help me to debug it

I've only recently learnt C++. I had a school project for making a BMI calculator. Unfortunately it is showing up errors beyond my scope of understanding. I'm not sure if I should use a different data type for my height and weight variables (double?) but please help me out`

#include <iostream>

using namespace std;

float bmi_calc(int height, int weight){
    float bmi_user = weight / height * height;
    return bmi_user;
}

int main()
{
    int weight_user;
    int height_user();

    cout << "Enter your weight in kilograms";
    cin >> weight_user;

    cout << "Enter your height in meters";
    cin >> height_user;

    cout << "Your BMI is " << bmi_calc(height_user, weight_user);
}