This version of Unity is unsupported.

Screen.width

public static int width;

Description

The current width of the screen window in pixels (Read Only).

This is the actual width of the player window (in full-screen it is also the current resolution).

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Example : MonoBehaviour { void Start() { //Output the current screen window width in the console Debug.Log("Screen Width : " + Screen.width); } }