How PixelMeasures Calculates Pixels, DPI and Bleed

For inch-based sizes:

pixels = inches × DPI

For millimeter-based sizes:

inches = millimeters ÷ 25.4
pixels = inches × DPI

For bleed:

bleed canvas width = trim width + bleed left + bleed right
bleed canvas height = trim height + bleed top + bleed bottom

When the bleed is the same on every side:

bleed canvas width = trim width + (2 × bleed)
bleed canvas height = trim height + (2 × bleed)

Photoshop

Use the pixel dimensions when creating a raster file. If the final result is print, set the physical size and resolution together so the file contains enough pixels.

Illustrator and InDesign

Use the physical trim size for the document. Add bleed in the document setup when the design reaches the edge. Export to PDF with the printer’s required marks and bleed settings.

Canva

Use the final trim size if the design tool has print bleed support. Turn on print bleed or crop marks when exporting for print, and check the printer’s template if available.

Figma

Figma is pixel-first. For print, use PixelMeasures to calculate the pixel canvas for your physical size and PPI target, then confirm final PDF or print handoff settings with the printer.

Pixels are whole units. A calculation can produce decimals when the physical size is metric. PixelMeasures rounds final pixel dimensions to the nearest whole pixel.

Example for A4 width at 300 DPI:

210 mm ÷ 25.4 = 8.2677 in
8.2677 × 300 = 2480.31 px
rounded result = 2480 px

Example for A4 height at 300 DPI:

297 mm ÷ 25.4 = 11.6929 in
11.6929 × 300 = 3507.87 px
rounded result = 3508 px

So A4 at 300 DPI is shown as 2480 × 3508 px.

A print file usually has three important zones:

Bleed is added outside the trim. Safe area is kept inside the trim.

For A4 with 3 mm bleed on each side:

width = 210 + 3 + 3 = 216 mm
height = 297 + 3 + 3 = 303 mm

At 300 DPI:

216 mm ÷ 25.4 × 300 = 2551 px
303 mm ÷ 25.4 × 300 = 3579 px

So an A4 bleed-ready canvas with 3 mm bleed is 216 × 303 mm, or about 2551 × 3579 px at 300 DPI.

PixelMeasures commonly shows these rows:

These are practical reference values, not universal requirements. Printer requirements, viewing distance, paper, ink, and production method can change the best target.

For platform image sizes, PixelMeasures prioritizes official platform documentation when available. When a platform does not publish a precise public pixel requirement for an asset, PixelMeasures labels the recommendation as a practical production target and explains the confidence level.

Platform pages should always include:

• the recommended working pixel size;
• the aspect ratio;
• crop or safe-area notes;
• file format and upload limits when available;
• the official or practical source basis;
• the last verified date.