How to check the DPI of an image (and change it to 300 DPI)
Updated 21 October 2026
Tool for this guide: DPI checker
Short answer: drop the image into the DPI checker. It shows the DPI saved in the file, the print size it gives in inches and centimetres, and the largest size it prints well at 300 DPI. To change it, use image to 300 DPI; the pixels stay exactly the same.
What DPI means
DPI (dots per inch), also called PPI, is a label that tells printers how big to print the image. It doesn't change the pixels:
| Same 3000 × 2000 photo at | Prints at |
|---|---|
| 72 DPI | 41.7 × 27.8 inches |
| 150 DPI | 20 × 13.3 inches |
| 300 DPI | 10 × 6.67 inches |
Print quality depends on the pixels. 300 DPI is the standard for sharp photo prints, books and brochures.
Check DPI online
- Open the DPI checker.
- Add JPG, PNG, WebP or TIFF images, as many as you like.
- Read the DPI, print size and the best size at 300 DPI.
Nothing is uploaded.
Check DPI on your computer or phone
- Windows: right-click the image → Properties → Details → Horizontal resolution.
- Mac: open in Preview → Tools → Show Inspector → the "i" tab shows Image DPI.
- Photoshop: Image → Image Size → Resolution.
- Phones: most gallery apps don't show DPI; use the online checker.
Change an image to 300 DPI
- Open image to 300 DPI.
- Add JPG or PNG images and keep 300 selected.
- Download. The image looks the same and the file size barely changes; the print size label is now 300 DPI.
If a print shop says the image is too small, it needs more pixels, not a different DPI. Upscale it first. Pixels needed at 300 DPI:
| Print size | Pixels needed |
|---|---|
| 6 × 4 in (15 × 10 cm) | 1800 × 1200 |
| 7 × 5 in | 2100 × 1500 |
| A4 (8.3 × 11.7 in) | 2480 × 3508 |
| 10 × 8 in | 3000 × 2400 |
More in image DPI for printing.
Questions
Why does my image say 72 DPI?
72 or 96 DPI is a common default for images made on computers and phones. It doesn't mean low quality; check the pixel size instead.
Can I check the DPI of a PDF?
A PDF doesn't have one DPI. Save the page with PDF to JPG at 300 DPI, then print or check that image.
How many KB is a 300 DPI image?
DPI doesn't decide the KB size. If a form needs 300 DPI and a size limit, compress first with compress to 100 KB or 50 KB, then set 300 DPI. Compressing saves a fresh file, so doing it last would reset the DPI.
Try it now
Check the DPI (resolution) saved in an image, see how large it will print, and change the DPI without touching the pixels.
Open dpi checker