WooCommerce sub-total minus discounts (Pixel)

I'm trying to place a conversion pixel on a WooCommerce site and they need the sub-total (minus discounts) to be passed into the pixel. Only problem is that I am unable to find any WooCommerce tags that would pass the Sub-total (minus discount) into the pixel. Does anyone know of a tag or other way of achieving this? I tried using "get_cart_subtotal()" but obviously that only passed the sub-total.