100 x X-Large S/W Packing Cardboard Boxes 20x20x28″. Perfect for large size items, and a good size for warehouse/ dispatch use at an economy price. This is the largest single wall box we distribute. Should not be used for heavy items (double wall boxes are recommended for heavy items). All stated dimensions are length x width x height.

These boxes have been manufactured to have the maximum internal dimensions that Yodel and Parcelforce allow to be sent in their network, under their standard 24hr or 48hr services. The internal dimensions of the boxes are 510x510x715mm (51x51x71.5cm). The external dimensions of the boxes are 516x516x727mm (51.6×51.6×72.7cm). All measurements are length x width x height. To calculate the size of this box using Yodel or Parcelforce’s volumetric calculation, simply use the below:

Yodel 24 or 48 – This states that the box must be less than 0.23 cubic metres. The external size of this box once assembled and taped is 0.52×0.52×0.73M = 0.20 cubic metres (less than their maximum of 0.23 cubic metres)

Parcelforce 24 or 48 – the length plus girth must equal less than 3 metres. In this case, the calculation using the external measurements of the box is 0.73+((52+52)*2) = 281cm (less than their maximum of 300cm).

The above box meets the courier profiles as you can see from the calculations above, and is the maximum size allowed under their services. Please note that if you overpack the box, or stretch it, then volumetric charging may apply. This box has been designed with all intent and purposes to have the maximum dimensions allowable for the above purposes, but we cannot take any responsibility for the courier service or any charging that may apply. Please check the dimensions yourself thoroughly before sending, once packed, to ensure it does not go oversize.