Shipping charges are automatically calculated by our system based upon physical weight. On very large / lightweight parts (eg a front wing) a volumetric charge may apply. Volumetric weight is calculated in Kg by multiplying the Length, Width and Height of the parcel in cm and dividing by 5000. This can not be calculated until the order is packed. If the volumetric weight exceeds the physical weight, we will notify you by email prior to despatch if the shipping charge indicated is insufficient, and inform you of the new shipping total, seeking your authorisation to proceed.