Use the free tool below: your data never leaves your browser — all work happens on your device, and nothing is uploaded to any server.
What this tool does
A big poster does not need a big printer. This poster tiling calculator splits a large poster into ordinary pages you can print at home, with a small overlap between neighbours so you can line the pieces up and tape them together. You enter the poster size, the paper size, and the overlap, and it tells you how many pages you need, how they are arranged, and what the finished size will be once the overlaps are trimmed. If you upload an image, it can also build the real tiled PDF: one page per tile, each holding exactly the slice of your picture that belongs there.
The tool runs entirely in your browser. Your image never leaves your device, which matters when the poster is a gift, a school project, or a design you have not published yet. Nothing is uploaded to any server, and the PDF is built on your own machine.
How tiling works
Tiling is simple once you see the moving part: the step. If your page is 30 cm wide and the overlap is 5 cm, each new tile only adds 25 cm of fresh poster, because 5 cm repeats the edge of the previous tile. The number of tiles across is therefore not the poster width divided by the page width. It is one tile for the first page, plus one more for every full step that remains. A 100 cm poster on 30 cm pages with 5 cm overlap needs four tiles across, because the tiles cover 30, then 55, then 80, then 105 cm. That last tile sticks out 5 cm past the poster edge, and you trim it.
The same arithmetic runs down the poster height. The finished size with overlap is always a little bigger than the poster itself, and the tool shows you that number so you are not surprised when the taped sheet measures wider than the design. Overlap is not waste. It is your alignment margin: without it, a printer that cuts a millimetre off an edge would leave a white crack down the middle of your poster.
A worked example
Take a poster 100 cm wide and 80 cm tall, printed on 30 cm square pages with 5 cm of overlap. Across, you need four tiles, as above. Down, you need three: the tiles reach 30, then 55, then 80 cm exactly. Twelve pages in total, arranged four across and three down. The printed sheet measures 105 cm wide before trimming, because the last column overhangs by 5 cm, and 80 cm tall. Trim the right-hand column by 5 cm and the overlap strips, tape the rows together, and the poster is 100 by 80 cm.
Try changing one input at a time and watch the tile count jump. Dropping the overlap from 5 cm to 2 cm on the same poster still needs four tiles across, because the step grows from 25 to 28 cm and three steps still do not reach 100 cm. Raising the page size to 40 cm, though, drops the count to three across. That is the trade worth testing before you print: a slightly larger page, or a smaller overlap, can save a whole row of pages.
Printing tips that save paper
Print one tile first, at 100 percent scale, and measure it with a ruler. Printer drivers love to add a “fit to page” shrink, and a 97 percent poster is a poster that will not line up. Turn off all scaling, and check that the printed tile really measures the page size you entered. If your printer cannot print to the very edge, that unprintable border eats into your tile: either shrink the page size in the tool to the printable area, or accept a white frame around the finished poster.
Mark each tile as it comes out, with its row and column, before you cut anything. A pile of twelve nearly identical slices is easy to shuffle, and one tile taped in the wrong place ruins the picture. Cut with a straight edge and a sharp blade rather than scissors, and tape from the back so the front stays clean. For a poster that will hang for months, glue the tiles to a backing board instead of taping them to each other: taped joins curl as the seasons change.
When tiling is the wrong choice
Tiling suits posters viewed from a metre or two away: classroom displays, party decorations, workshop charts, and prototype layouts. It is a poor choice for a photograph you will inspect up close, because the seams will always show if you look for them, and for anything that must survive rain or handling, because paper joins are the first thing to fail. In those cases a print shop’s single large sheet is worth the price. Also reconsider if your poster is mostly one flat colour: seams show most on flat colour, and least on busy photos and illustrations.
One more honest limit: this tool tiles rectangles. If your design is a circle, a star, or an irregular shape, the tile grid still works, but the outer tiles will carry a lot of blank paper. That is fine for a one-off, but wasteful at volume. Measure twice, print one test tile, and only then commit to the full set.