Equal panels do not fold flat
The most common mistake on a folded leaflet is dividing the flat width straight by the number of panels. In a roll fold the inner panel is wrapped by the outer ones, so equal widths leave it pinched at the crease: it bulges and the edge gapes. The panels that tuck in have to be cut slightly narrower.
How it is calculated
The reduction range used across the print trade is 1.5 to 3 mm, about a sixteenth to an eighth of an inch. The two outer panels keep one shared width, each tucked panel loses a further step, and the base width is solved backwards so the panels still add up to the flat width. Z and accordion folds are simply divided equally. Current as of October 2026.
Limits and disclaimer
Because the reduction depends on paper thickness, no default is supplied; you enter it. Only panel widths are returned, not fold coordinates or crease placement. Gate folds and cross folds are not supported either, so check a folding dummy with your printer.
Frequently Asked Questions
In a roll fold the inner panel is wrapped by the ones outside it. Keep every panel the same width and the inner one is pinched at the crease, so it bulges and the edge gapes open.
It depends on paper thickness. The range used across the print trade is 1.5 to 3 mm, roughly a sixteenth to an eighth of an inch; confirm the exact figure with your printer for your stock.
No. Accordion and Z folds zigzag rather than nesting, so the panels are simply divided equally. This tool applies no reduction to those styles.