How do I calculate the volume of a parcel with unequal sides? In this case, the longest dimensions (length x width x height) are used to calculate the volume (dm3). Gerelateerde vragen What are the maximum dimensions of a package? On which days can DHL Europlus deliver parcels? Is my package destined for Belgium automatically insured? Can I use DHL Europlus to ship a letterbox parcel to Belgium? I cannot send my parcels via a PostNL parcel and letter machine, why is that?