FROM PIXELS TO PAPER
Calculate your print size
Choose a JPEG or PNG to read its dimensions, or enter the pixels yourself. Set your print provider’s target PPI. The starting values are an example.
Example result · 300 PPI
12 × 18 inches
30.48 × 45.72 cm
Width × height for 3,600 × 5,400 pixels. Values shown to at most two decimal places.
How to convert pixels to cm
Size in centimetres = pixels ÷ PPI × 2.54. Apply the formula separately to the width and height. The calculator above does both conversions for you and keeps the matching inch values beside the result.
At 300 PPI, one centimetre contains about 118 pixels. A 3,000-pixel side therefore covers 25.4 cm; at 150 PPI, the same pixels cover 50.8 cm but supply half as many pixels per printed inch.
The calculation
Print size in inches = image size in pixels ÷ pixels per inch. Calculate both the width and the height. To convert inches to centimeters, multiply by 2.54.
For example, a 3,600 × 5,400 pixel image at 300 PPI prints at 12 × 18 inches, or 30.48 × 45.72 cm. At 150 PPI the same pixels cover 24 × 36 inches. That larger print has half as many pixels per inch; it has not gained detail.
| Image pixels | At 300 PPI | At 150 PPI |
|---|---|---|
| 1,200 × 1,800 | 4 × 6 in | 8 × 12 in |
| 2,400 × 3,000 | 8 × 10 in | 16 × 20 in |
| 3,000 × 4,000 | 10 × 13.33 in | 20 × 26.67 in |
| 3,600 × 5,400 | 12 × 18 in | 24 × 36 in |
| 4,800 × 6,000 | 16 × 20 in | 32 × 40 in |
300 PPI is a useful planning target for detailed prints. It is not a guarantee of quality: source sharpness, compression, paper, the printer and viewing distance still matter. A print provider may specify a different target. Adobe's print-resolution guidance recommends 300 PPI unless the printer asks for another value.
Check the pixels after cropping
Suppose your original is 4,000 × 6,000 pixels, a 2:3 shape. Cropping it to 4:5 while keeping the full width leaves 4,000 × 5,000 pixels. The removed 1,000 pixels of height cannot contribute to the print.
That crop can produce an 8 × 10 inch print at 500 PPI or a 16 × 20 inch print at 250 PPI. It does not meet a 300 PPI target at 16 × 20. Repositioning the crop changes which pixels remain, not how many there are.
When the source and frame have different shapes, crop or fit the artwork first. Dividing the original dimensions can overstate the resolution available in the final composition.
Adding a white border does not create image detail
A fit layout preserves the whole artwork inside a different-shaped canvas. The empty border contributes pixels to the file, but it does not add detail to the artwork. For a 300 PPI plan, the artwork itself must still have enough pixels for the space it occupies. Check both the image area and the final page size.
“300 DPI” is not an image enhancement
PPI describes image pixels per printed inch. DPI describes printer dots, although the terms are often mixed together in listing copy and software. A density tag can tell printing software an intended physical size. Changing that tag alone leaves the pixel count unchanged.
A 1,200 × 1,800 pixel image remains the same image when its density tag changes from 72 to 300. At 300 PPI its print size is 4 × 6 inches. Adobe explains the distinction between pixel dimensions and printed resolution.
What to do with a small source
Return to the original design, scan or full-resolution photograph if you can. Otherwise offer smaller print sizes that suit the file. Upscaling generates more pixels, but it cannot guarantee recovery of missing original detail. SnippetSafe does not upscale your artwork.
Before publishing, open an exported file at 100% zoom and order a proof at the largest size you intend to advertise. Then include only the print sizes and ratios you have checked in the buyer's instructions.