The interior dimensions are important properties in the general construction of a box, and accurate methods of measurement are required for research work, routine control, and acceptance testing for conformance to specifications. For containers to carry and protect their contents effectively and efficiently, the containers must be of proper and uniform size. This method involves a degree of human judgment and assumes careful and accurate placement and reading of specified apparatus.

Method A, Measuring Lot of Boxes-determines if a lot (i.e., production run) is within specified tolerance for each dimension (length, width, and depth). A minimum of five specimens are measured. The test result for each dimension is the individual measurements of that dimension on all specimens. If any test result is outside of a specified tolerance, that box specimen should be re-measured using Method B to determine final test results.

Method B, Measuring Single Boxes-determines if one particular box is within specified tolerance for each dimension. The test result for each dimension is the average of all measurements of that dimension.