Print Bleed, Trim & Safe Margin Calculator

A printed sheet is not cut with perfect accuracy. Machines shift by a fraction of a millimetre, so artwork that stops exactly at the page edge can leave a thin white line along one side. To avoid it, printers ask for bleed: background colour and images that extend a few millimetres beyond the trim line, which are then cut off. This calculator shows the three boxes that a print file needs and converts them to pixels for raster artwork.

The three boxes

The trim size is the finished page after cutting. The document size is the trim plus the bleed on every side, so with 3 mm of bleed it is 6 mm larger each way. The safe area is inside the trim by a margin, commonly 3 to 5 mm, and holds text and logos that must not be cut by accident or sit too close to the edge. The diagram shows them as nested rectangles: red outer band, black trim line and blue dashed safe area.

A worked example

Press Sample for A4, 210 by 297 mm, with 3 mm bleed, 5 mm safe margin and 300 dpi. The page shows trim 210 × 297 mm, document size with bleed 216 × 303 mm and safe area 200 × 287 mm. In pixels at 300 dpi the trim is 2480 × 3508, the document with bleed is 2551 × 3579 and the safe area is 2362 × 3390. Build the file at the larger size, extend backgrounds to its edges and keep all text inside 200 by 287 millimetres. Export a PDF at the document size.

Inches

Switch the unit to inches and the defaults become 0.125 in bleed and 0.25 in safe margin. A US business card of 3.5 by 2 inches becomes a document of 3.75 by 2.25 inches, with a safe area of 3 by 1.5 inches. At 300 dpi that is 1050 × 600 pixels for the trim, 1125 × 675 with bleed and 900 × 450 for the safe area. A 6 by 9 inch trade paperback page becomes 6.25 by 9.25 inches with bleed, which is 1875 by 2775 pixels. Changing units converts the size and resets the margins to that unit’s defaults.

Choosing values

Three millimetres, or 0.125 inch, is the most common bleed, but some printers ask for 5 mm or have different rules for large formats and for binding. The safe margin should be larger for items that are trimmed by hand or bound with a spine. Always read the printer’s template and use their numbers when they differ from the defaults here. The resolution field matters only for raster files; vector artwork has no pixel size.

Resolution

For photographs and raster layouts, 300 dpi at the final print size is the usual target. At 150 dpi the pixel sizes are half of the 300 dpi values. Large posters seen from a distance can use less. Do not enlarge a small image to reach the pixel count, because the extra pixels add no detail. The calculation is just inches times dpi, rounded.

Edge cases

A zero bleed is allowed and returns trim equal to document size. If the safe margin is too large for the page, the page shows an error. Bleed is not added for folded edges that are not cut, and spreads or booklets may need bleed only on the outer edges. Crop marks need extra space outside the bleed; add them in your layout software if the printer asks.

Limits

The calculator provides sizes, not templates, and it does not build the print PDF. Paper sizes are the nominal trim sizes of the standards listed. Everything is computed in your browser.

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