SizeKitSizeKit reference
Print DPI Calculator
Calculate DPI from image pixels and physical size, or pixels from size and DPI. Three modes for print, scan, and design workflows.
SizeKit
Common results first
These cover frequent one-off checks. Use the full calculator below only for custom values.
SizeKit
Three calculation modes
Pick the mode in the calculator that matches what you already know.
SizeKit
DPI calculator
Switch mode in the dropdown. Inputs not used by the chosen mode are ignored.
SizeKit
Formulas
Explicit conversion for each mode.
Mode 1: pixels = round((mm / 25.4) x DPI). For inches: pixels = round(inches x DPI). Mode 2: inches = pixels / DPI; mm = inches x 25.4. Mode 3: DPI = pixels / inches (use the matching axis: horizontal pixels / horizontal inches).
SizeKit
Use this tool for
When the print DPI calculator is the right answer.
- Checking the actual DPI of a scanned document or photo.
- Sizing a digital file for photo lab, business card, or poster print.
- Confirming whether an image has enough pixels to print at the desired size and quality.
- Converting between print measurements (mm, cm, inch) and digital pixels with a target DPI.
SizeKit
Do not use this tool for
Common confusions that lead users to the wrong tool.
- Mouse DPI / gaming sensitivity (Valorant, CS2, Apex). Those are pointer counts per inch of mouse movement. They have nothing to do with image DPI. Use the gaming mouse software (e.g. Logitech G HUB, Razer Synapse).
- Screen pixel density when reading specs. Phone and laptop screens use PPI (pixels per inch) as a hardware spec. This calculator can compute it, but the value is fixed by the device.
- Setting DPI inside Photoshop / Lightroom without resampling. Changing DPI metadata does not change the actual pixel count. The print size changes, the image data does not.
- Web image sizing. Web images use absolute pixel counts. DPI is irrelevant on screen. Use the Aspect Ratio Calculator.
SizeKit
DPI quality reference
Recommended DPI for common use cases.
| Use case | Recommended DPI | Notes |
|---|---|---|
| Photo print, fine art | 300 DPI | Industry standard. Anything more usually invisible. |
| Office document print | 150 DPI | Acceptable for text and basic graphics. |
| Large poster (viewed at distance) | 100-150 DPI | Viewer is 1+ meter away; lower DPI is acceptable. |
| Billboard (viewed from far) | 20-50 DPI | Distance hides low resolution. |
| On-screen / web | 72 or 96 DPI | Convention only; screens use absolute pixels. |
| Newspaper print | 150-200 DPI | Lower-quality paper limits detail. |
SizeKit
Source and calculation method
Formulas and conventions used by SizeKit.
SizeKit
Related paths
Use a reference page if you know the size name; use a calculator only when your value is custom.
SizeKit
FAQ
Practical calculator questions.
What is DPI?
DPI (dots per inch) is the print density of an image. It defines how many pixels fit into one printed inch. SizeKit DPI refers to image print resolution, not mouse pointer sensitivity.
How do I calculate DPI from pixels?
Divide the image pixel width by the printed width in inches. DPI = pixels / inches. Example: a 2400 px wide image printed at 8 in is 300 DPI.
What DPI is good for printing?
300 DPI is standard for photo and high-quality print. 150 DPI is acceptable for office documents. 72 DPI is screen-only.
What is the difference between DPI and PPI?
DPI is the print measure (dots per inch); PPI is the screen measure (pixels per inch). Most software uses them interchangeably, but the underlying concept differs.
Is this a mouse DPI calculator?
No. This tool is for image and print DPI. For mouse DPI / gaming sensitivity (Valorant, CS2, Apex), use your gaming mouse software.