Poster Tiler – Print a Big Picture on Several Pages

You do not need a large-format printer to make a big poster. A poster tiler cuts your picture into page-sized pieces and prints them on ordinary A4 or Letter paper; you trim the margins and join the pages into one large print. Choose how many pages wide the poster should be, or its width in centimetres or inches, and this tool works out the grid, adds cut marks and optional overlap strips for gluing, and writes one print-ready PDF. Nothing is uploaded.

How to use this tool

1. Choose a picture — the higher its resolution, the sharper the poster.
2. Set the size in pages across, or the width in cm or inches; the height follows the picture.
3. Pick the paper and orientation, a margin your printer can handle, and an optional overlap.
4. Print the PDF at 100%, trim along the marks and assemble the pages by their labels.

Formula

poster width = pages × (page − 2 × margin) − (pages − 1) × overlap; pages down = ⌈(poster height − overlap) ÷ (printable height − overlap)⌉

The poster height is width × picture height ÷ picture width. When you give the width in cm or inches, pages across = ⌈(width − overlap) ÷ (printable width − overlap)⌉. Each page prints its part of the picture at up to 200 dpi; the last row and column are cut where the picture ends. Print resolution = picture width in pixels ÷ poster width in inches.

Example

A 4000 × 3000 photo, 3 A4 pages across, 10 mm margins and no overlap: each page prints 190 × 277 mm, the poster is 3 × 190 = 570 mm wide and 570 × 3000 ÷ 4000 = 427.5 mm high, so it needs ⌈427.5 ÷ 277⌉ = 2 rows — 6 pages. The photo then has 4000 ÷ 22.4 in ≈ 178 pixels per printed inch.