Where do I find the pixel width?

Any image editor reports it, and so does the file's own info panel: macOS Finder shows it under Get Info, Windows under Properties → Details. It is the first of the two dimensions, usually written as width × height.

The file says 300 DPI already. Why is the result lower?

A DPI tag is a note stored inside the file; it changes nothing about how many pixels exist. A 500 px image can carry a 300 DPI tag and still cover 4.2 cm. What the press works from is pixels divided by inches, which is what this page calculates.

Can upscaling raise the covered width?

It raises the pixel count, so the arithmetic returns a larger number. Whether that number is honest depends on the artwork: on illustration a model can rebuild plausible edges, on lettering it redraws letterforms and a redrawn letter is the wrong letter across the whole run.

Print size calculator: what width does this file actually cover?

Two divisions decide whether a file survives the size it was ordered at, and both can be done before anything is loaded onto the press. Enter the artwork's pixel width and the width you intend to print; what comes back is the resolution that width implies and the width the pixels genuinely cover.

Artwork width in pixels

The width your image editor reports — not the file size in MB

Print width

Common placements

Enter a pixel width to see the numbers.

800 px	6.8 cm / 2.7 in at 300 DPI
1,000 px	8.5 cm / 3.3 in
1,500 px	12.7 cm / 5.0 in
2,000 px	16.9 cm / 6.7 in
3,000 px	25.4 cm / 10.0 in
4,000 px	33.9 cm / 13.3 in
4,032 px — long edge of a current phone photo	34.1 cm / 13.4 in
One inch	2.54 cm — the constant both divisions run through

Where the two numbers come from

Neither figure is a rule of thumb; both fall out of arithmetic that takes a second. The first tells you what the press receives at the size you asked for. The second tells you the largest size this file reaches without inventing detail.

Effective resolution = pixel width ÷ (print width in cm ÷ 2.54)
Covered width = pixel width × 2.54 ÷ 300
Nothing here reads the file's DPI tag — a tag is metadata, not a measurement

Why the artwork looks better on the monitor than on the shirt

A display packs roughly 72 to 160 pixels into an inch and lights each one from behind. Cotton has no backlight, spreads ink slightly into the weave, and is viewed from arm's length rather than through a zoom control. The same file therefore reads as sharp on screen and soft on the garment, which is why the decision belongs to a number rather than to an impression.

The result is a measurement, not a verdict

A figure above 300 does not certify the artwork, and one below 150 does not condemn it. Resolution says nothing about whether strokes are thick enough to survive a transfer, whether letters are tall enough to stay open, or whether the edges carry compression damage. Those limits are physical and they do not move with pixel count.

What this page does not do yet

It does not read your file. The pixel width is typed in, because measuring an uploaded file is the processing pipeline's job and that pipeline is not open to the public yet. When it is, the same two numbers will come from the file itself instead of from your keyboard — the arithmetic will not change, only where the input comes from.

FAQ

Where do I find the pixel width?: Any image editor reports it, and so does the file's own info panel: macOS Finder shows it under Get Info, Windows under Properties → Details. It is the first of the two dimensions, usually written as width × height.
The file says 300 DPI already. Why is the result lower?: A DPI tag is a note stored inside the file; it changes nothing about how many pixels exist. A 500 px image can carry a 300 DPI tag and still cover 4.2 cm. What the press works from is pixels divided by inches, which is what this page calculates.
Can upscaling raise the covered width?: It raises the pixel count, so the arithmetic returns a larger number. Whether that number is honest depends on the artwork: on illustration a model can rebuild plausible edges, on lettering it redraws letterforms and a redrawn letter is the wrong letter across the whole run.

All guides