Build a raster file from a label, packaging panel or paper specification in millimeters. Keep finished trim dimensions and optional bleed separate so the pixels you export match the intended production canvas.
Prepare millimeter artwork
- Enter the finished width and height, or choose A6, A5 or A4.
- Enter target PPI and, when specified, bleed per edge in millimeters.
- Review both trim and bleed results; explicitly choose which dimensions to send to Image Resizer.
Convert millimeters to the required pixel grid
First calculate inches = mm ÷ 25.4. Then multiply by PPI: px = mm ÷ 25.4 × PPI. An A4 sheet at 300 PPI has exact dimensions of about 2480.315 × 3507.874 pixels, rounded here to 2480 × 3508.
The rounded result is a production target, not proof of an existing file’s quality. If a specification sets a strict minimum density, review the exact answer and select upward rounding in your production workflow where needed.
Add bleed to both sides of each edge
For bleed b on every edge, the canvas width is trim width + 2b and the height is trim height + 2b. A 100 × 150 mm label with 3 mm bleed needs a 106 × 156 mm canvas. At 300 PPI, the nearest whole-pixel trim result is 1181 × 1772; the bleed canvas is 1252 × 1843 pixels.
Both calculations remain in the report. Choose trim when checking the finished panel and bleed when preparing an export that must extend past the cut. Bleed is not a safe area: important text normally stays inside the trim according to the supplier’s template.
Paper presets and custom packaging sizes
A6 is 105 × 148 mm, A5 is 148 × 210 mm and A4 is 210 × 297 mm. Enter custom dimensions for a package panel; folds, glue areas and multiple panels may require a dieline beyond a simple rectangle.
| Size | Millimeters | Rounded pixels at 300 PPI |
|---|---|---|
| A6 | 105 × 148 | 1240 × 1748 |
| A5 | 148 × 210 | 1748 × 2480 |
| A4 | 210 × 297 | 2480 × 3508 |
Image pixels and CSS pixels
CSS defines 96 CSS pixels per CSS inch for layout. That relationship is not the physical density of every screen, nor a required density for a printed image. Here, PPI is your explicit print assumption; browser zoom does not change the file’s stored pixels.
Frequently asked questions
Does 3 mm bleed add 3 or 6 mm to the width?
It adds 6 mm when there is 3 mm on both the left and right. The same applies to top and bottom.
Which result should I send to the resizer?
Choose the finished trim or the canvas including bleed according to the output specification. The calculator keeps both so they are not silently mixed.
Does the A4 preset include bleed?
No. It starts from the 210 × 297 mm finished size. Add the bleed requested by your printer separately.