unity - Resize sprite to match camera width?

I'm trying to resize my small background sprite to match the screen width of the user's device.

This is what I'm trying

// Use this for initialization
void Start () {
    // Set filterMode
    SpriteRenderer sr = (SpriteRenderer) GetComponent("Renderer");

    sr.sprite.texture.filterMode = FilterMode.Point;

    // Get scaling
    float multiplier = Camera.main.rect.width / sr.sprite.bounds.size.x;

    // Scale
    transform.localScale = localScale * multiplier;
}

It seems there is a problem with the measure I get from the Camera width, I also tried Screen.width but it seems it returns the value in pixels.