Corrugated Box Blank Size Calculator
Estimate the flat blank size of a standard corrugated box before tooling. Enter the internal length, width, and height of a regular slotted carton (RSC / 0201) and pick the construction to get the external size and the flat sheet dimensions.
Enter the internal dimensions of a standard RSC (0201) box.
Result
Estimate for a single-piece RSC (0201). The blank length includes a 40 mm glue joint; a production cutting forme accounts for exact scoring and flute crush. Use it to gauge board consumption and sheet size, not as final die dimensions.
How the blank size is worked out
A regular slotted container (RSC, style 0201) is cut and creased from a single flat blank. The four walls wrap around the box, so the blank length spans all four panels plus a glue joint:
Blank length = 2 × (L + W) + glue joint
Blank width = Height + Width (top & bottom flaps)
The external size adds the board caliper to each internal dimension. Thicker constructions, 5-ply versus 3-ply, add more. This is an estimate for gauging board consumption and sheet size; a production cutting forme accounts for the exact flute, scoring, and crush. To choose the construction first, see 3-ply vs 5-ply.
Common questions
What is an RSC (0201) box?
A Regular Slotted Container is the most common corrugated box style, a single-piece blank where all flaps are the same length and the outer flaps meet in the middle. It is the standard shipping carton, and this calculator is built for that style.
Why is the external size bigger than what I typed?
Because you enter the internal (product) dimensions, and the board has thickness. The external size adds the board caliper to each side, more for thicker 5-ply than thin E-flute, which matters when the box itself has to fit a pallet or a shelf.
Is this exact enough to order a cutting die?
Treat it as an estimate. It is accurate for planning board usage and sheet size, but a final die accounts for the exact flute, scoring allowances, and crush. Send us your internal dimensions and we'll produce exact manufacturing drawings.
More calculators
Written by LeRoy Print Packs, a printing and packaging manufacturer making cartons, corrugated boxes and labels in-house. Get a quote