Doesn’t this sound easy? Take a box, use your measuring tape and voila! You know the size. Since we manufacturers work with inside dimensions it is important not only to know how to either convert outside dimension to inside dimensions or properly measure the inside using the proper allowances. You also will need to know the Flute of the carton to do this accurately.

Let’s start with measuring the outside and converting it to inside dimensions. And for the sake of simplicity, we’ll say it is a C Flute RSC Carton. Dimensions are always presented as Length, Width, Depth. Corrugated companies always work in 1/16th, never 1/32″ or 1/64″. Take the largest dimension, measure it. Once you have that dimension subtract 5/16″.   Example: Length dimension is 9 5/16, the inside dimension is 9 inches. Next take the width dimension, measure that and subtract 5/16″. Example: If the dimension is 6 5/16, the inside dimension is 6″. Finally, the depth, this is the “height” of the box. For this one you take your measurement and subtract 5/8″. Example: If the depth is 10 5/8″, your inside dimension becomes 10″.

The other option is to measure the inside and add a folding allowances. Again, for the sake of simplicity, we’ll say it is a C Flute RSC Carton. With this option, the first thing you need to do is open the carton up. Best way to do this is at the glue lap. Once the carton is open, lay it down flat with the inside of the box facing you. As before we will start with the length panel. Always use the length panel that’s in the middle. Measure this dimension and add 3/16″ for roll over allowances. Measure the middle width panel and add 3/16″ for allowances. Finally, measure the depth and add 3/8″. And, as the old adage says, “Measure twice”.

To be honest, the best way to do this is simply call or email us! We can help not only measure the box but price it, produce it, and deliver it on time! 630-323-1354. [email protected]