Image DPI checker
Check the file. Choose the print size.
An image has pixel dimensions and may also contain a print-density record. Read those records separately, then calculate the physical size at the density you choose. Your file stays on this device and is not changed.
Up to 20 MiB. Header and metadata inspection happens in this browser; your image is not uploaded or changed.
This is a 1,200 × 900 software-drawn PNG with a deliberately assigned density record. It is a parser example, not a camera image or print-quality benchmark.
From image pixels to a print-size calculation
- Choose a PNG or JPEG. Compare the encoded dimensions with the dimensions after a supported orientation record.
- Read the density records and their source. Missing, unitless, invalid and conflicting values have different meanings; none is silently replaced with 72, 96 or 300 DPI.
- Enter the intended print density. The calculator divides each pixel dimension by pixels per inch and also shows centimeters and millimeters. It does not resample or rewrite the image.
The same pixels, two print sizes
A 3,000 × 2,400-pixel image at a chosen 300 pixels per inch has a calculated size of 10 × 8 inches (25.4 × 20.32 cm). At 150 pixels per inch, those same pixels cover 20 × 16 inches. Changing a density tag does not create additional captured detail.
What the file can tell you
The reader inspects PNG pHYs and selected JPEG JFIF/EXIF density records. PNG eXIf is read for IFD0 orientation only. It shows recorded units and numeric values rather than treating a missing tag as a standard density. A unitless record can describe a pixel aspect ratio but cannot establish inches or centimeters.
Different programs can write different density records into the same file. Keep those observations separate. These editable records do not establish camera origin, AI generation, authorship or print quality.
DPI is common file and printing terminology. For this image-size calculation, the chosen value is image pixels per inch (PPI); a printer’s hardware dots per inch is a separate measure. Suitable print density depends on the process, image and viewing distance.
Image density questions
Why does my image have no DPI value?
A valid image can contain pixel dimensions without a supported physical-density record. That does not make the image low quality. Enter a density explicitly to explore a print size; the chosen value remains a calculation assumption, not a newly discovered file property.
Does changing a picture to 300 DPI make it sharper?
Changing only a metadata value changes how software may interpret its physical size. It does not add pixels or restore detail. This checker does not change DPI tags or resample images.
Which image records are supported?
This bounded reader supports PNG pHYs and selected JPEG JFIF/EXIF density records, plus supported EXIF orientation in JPEG or PNG. Other formats and metadata families are outside its scope. It does not decode the pixels or certify that the whole image is valid; this is not a complete metadata or image-conformance audit.
Does this prove an image is real or AI-generated?
No. Pixel dimensions and editable density fields do not establish origin. Preserve the original file and inspect separate source or provenance evidence for that question.