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Image DPI Calculator

Work out how large a picture can be printed, what resolution an existing print size really has, or how many pixels you need for a given size. Enter any two of pixels, print size and DPI, choose inches, centimetres or millimetres, and get the answer with plain-language guidance on whether the quality is good enough, from 300 DPI photos to 150 DPI posters.

Image Info & Metadata Runs in your browser

Calculate DPI, Print Size or Pixels

No image is needed: type any values and calculate. Adding a file only fills in its pixel size and shows the DPI saved inside it.

What do you want to find?
px
px
300 for photo prints, 150 for large posters, 72 to 96 for screens.
Drag and drop an image to read its pixel size and DPI (optional) here, or click to browseOptional. Fills in the pixel size and shows any DPI saved in the file. Nothing is uploaded.

How to Use the Image DPI Calculator

  1. Choose what you want to find: print size, DPI or pixels needed.
  2. Enter the known values. The fields you need appear; you can also add an image to fill in its pixel size automatically.
  3. Press Calculate.
  4. Read the result, the quality guidance and the table showing the same picture at common DPI values.

About This Tool

Photographers and designers preparing files for print, people ordering posters or canvases, and anyone wondering whether a phone photo is big enough for a certain size.

Input: Pixels / inches / cm  ·  Output: DPI / size / pixels.

Features and Limitations

Features

  • Three calculations in one tool: print size, DPI and required pixels.
  • Inches, centimetres and millimetres.
  • Print-quality guidance from excellent (300 DPI) to too low.
  • Table of print sizes at 72, 150, 200, 240 and 300 DPI.
  • Optional image upload reads pixel size and embedded DPI without uploading the file.

Limitations

  • DPI and PPI are used interchangeably here; printers use their own dot patterns, so this is the image resolution at the print size.
  • The quality labels are common rules of thumb. Viewing distance matters: a billboard needs far less than a passport photo.
  • The DPI tag stored inside a file does not change the pixels, so a 72 DPI tag does not mean a low-quality picture.
  • Results are rounded for display.
  • Processing happens on your device, so very large files depend on your browser's available memory.

Example

A 3000 × 2000 px photo at 300 DPI prints at 10 × 6.67 inches (25.4 × 16.9 cm). The same photo at 150 DPI prints at 20 × 13.3 inches.

Frequently Asked Questions

How is DPI calculated?

DPI = pixels ÷ print size in inches. A 3000 px wide image printed 10 inches wide has 300 DPI.

What DPI do I need for printing?

300 DPI is the usual target for photos and sharp prints, 150 to 200 DPI is acceptable for large posters viewed from a distance, and 72 to 96 DPI is enough for screens.

Does changing the DPI in an image make it sharper?

No. Changing only the DPI tag does not change the pixels. To print larger at the same DPI you need more pixels.

What is the difference between DPI and PPI?

PPI describes pixels per inch in a digital image, while DPI strictly describes printer dots per inch. In everyday use the two terms are swapped freely.

How many pixels do I need for an A4 print at 300 DPI?

A4 is 21 × 29.7 cm (8.27 × 11.69 inches), so about 2480 × 3508 pixels. Choose Pixels needed, enter 21 and 29.7 with centimetres selected, and 300 DPI.

Related Tools

More like this: all Image Info & Metadata tools, all Image & Design tools or the TinySandy home page.