Guides / 02—08
Separate a box's inside and outside sizes
Content capacity and shipment dimensions answer different questions.
Check the box specification
A listed box size often describes its internal space. Confirm whether the supplier means internal or external size; wall thickness creates a difference.
Use the right set of numbers
Use inside measurements to test whether the object and protection fit. Use the closed parcel's outside measurements for shipment volume. Do not swap the two because they look close.
Test a real box
A sample may change shape when assembled, especially if the material bows. Measure one assembled box and retain both sets of dimensions for repeat shipments.