CameraExtensions.cs

using UnityEngine;

public static class CameraExtensions
{
    public static float GetOrthographicSizeFromWorldWidth(this Camera camera, float width)
    {
        return width / camera.aspect * 0.5f;
    }

    public static float GetOrthographicSizeFromWorldHeight(this Camera camera, float height)
    {
        return height * 0.5f;
    }

    public static float GetOrthographicSizeFromWorldSize(this Camera camera, Vector2 size)
    {
        return GetOrthographicSizeFromWorldSize(camera, size.x, size.y);
    }

    public static float GetOrthographicSizeFromWorldSize(this Camera camera, float width, float height)
    {
        return Mathf.Max(GetOrthographicSizeFromWorldWidth(camera, width), GetOrthographicSizeFromWorldHeight(camera, height));
    }
    
    public static void SetOrthographicSizeToFitSize(this Camera camera, Vector2 size)
    {
        camera.orthographicSize = GetOrthographicSizeFromWorldSize(camera, size.x, size.y);
    }

    public static void SetOrthographicSizeToFitSize(this Camera camera, float width, float height)
    {
        camera.orthographicSize = GetOrthographicSizeFromWorldSize(camera, width, height);
    }
}