This is a small utility script I use in simple 2D Unity games to world coordinates. I'd probably make this static and just pass in a cam object in the future so I can call it anytime.

CameraBoundaries.cs

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

public class Boundary : MonoBehaviour
{
    Camera cam;
    public float width, height;

    // Start is called before the first frame update
    void Start()
    {
        cam = Camera.main;
    }

    // Update is called once per frame
    void Update()
    {
        
    }

    void FindBoundaries()
    {
        width = 1 / (cam.WorldToViewportPoint(new Vector3(1, 1, 0)).x - 0.5f);
        height = 1 / (cam.WorldToViewportPoint(new Vector3(1, 1, 0)).y - 0.5f);
    }
}