How to Design a Brochure Grid in Millimeters
Print layouts like brochures and leaflets rely on four key concepts: trim size, bleed, safe area, and the column grid. Trim size is the final cut paper size. Bleed extends backgrounds and images a bit beyond that — usually 2-3mm — to cover any slight shift during trimming. The safe area sits inward from the trim line by your margin, and important elements like text and logos must stay inside it to avoid being cut off.
For example, an A4 sheet (210×297mm) with a 15mm margin, 3 columns, and a 5mm gutter gives a safe area of 180×267mm. Total gutter width is 5 × 2 = 10mm, so each column comes out to (180 − 10) ÷ 3 = 56.7mm. Adding a 3mm bleed brings the full working size to 216×303mm.
This calculator takes paper size (A4, A5, or Letter), margin, column count, gutter, and bleed, then computes trim size, work size, safe area, and column width all at once — saving setup time on print design projects.
Frequently Asked Questions
To cover slight shifts during trimming by extending backgrounds 2-3mm beyond the final size.
A4 suits content-heavy brochures; A5 fits leaflets and simple flyers.
Keep text and logos 3-5mm inside the trim line to avoid cutoff.