Set the box up square
Measure a box that is open and standing, not a flat one.
Measure inside
Measure from inside wall to inside wall. Box sizes are normally quoted as inside dimensions.
Length first
Length is the longer side of the opening, width the shorter.
Height last
From the inside floor to the top of the side wall, not to the top of the flaps.
Note the wall count
Count the fluted layers at a cut edge, or read the Box Maker's Certificate.
Common mistakes
- Measuring the outside. On multi-wall board the outside is noticeably larger.
- Swapping length and width.
- Measuring height to the top of the flaps.
- Measuring a box that is crushed, bulged or not square.
When you need the outside size, for pallet overhang or trailer fit, measure that separately and label it clearly.
Continue through the size guide
Send your measurements
Inside dimensions, wall count and quantity. A partner supplier follows up with a quote.