Free Screen Size Calculator for PPI, Physical Dimensions, Pixel Pitch, and PPD
Use this screen size calculator to combine diagonal size and resolution into PPI, physical width and height, pixel pitch, aspect ratio, field of view, and pixels-per-degree estimates.
Run the live browser test
| Scenario | Diagonal | PPI | Pixel pitch |
|---|
12 practical features in this screen size calculator
Diagonal size input in inches
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Resolution width and height
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Automatic aspect-ratio reduction
Built into this page as an interactive or diagnostic capability, not just a static explanation.
PPI calculation
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Physical screen width
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Physical screen height
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Pixel pitch in millimeters
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Viewing-distance input
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Horizontal field-of-view estimate
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Pixels-per-degree estimate
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Reverse diagonal from target PPI
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Scenario comparison table
Built into this page as an interactive or diagnostic capability, not just a static explanation.
How to read the diagnostic signal
| Signal | Useful interpretation | Important limitation |
|---|---|---|
| Stable repeat result | More useful for comparison than a single isolated sample | Still depends on the current browser, OS, and device state |
| Large change after one controlled adjustment | Good clue that the changed variable matters | Correlation is not always proof of root cause |
| Missing or inconsistent browser event | Useful troubleshooting evidence | Does not electrically inspect hardware components |
| Exported session summary | Helps compare before/after changes | Only as good as the test conditions you record |
Worked example: run the same test twice, change one relevant setting, then repeat it. A consistent change across repeated runs is more informative than a single isolated number.
Six short lessons for better testing
Control one variable
Keep device settings, browser zoom, and test mode constant before comparing results.
Repeat the measurement
One run can be noisy. Repeat the same test and look for a stable pattern.
Separate browser from hardware
Browser events are useful diagnostics, but they do not expose every firmware or electrical detail.
Use the right metric
Choose timing, accuracy, count, support, or geometry metrics that match the problem you are investigating.
Record context
Save the device, connection type, relevant settings, and test condition with any result you compare later.
Interpret, do not overclaim
Treat the page as a practical diagnostic aid rather than a laboratory certification instrument.
Complete the diagnostic workflow
Three-question diagnostic quiz
Recent saved milestones on this device
Continue without a dead end
Free Screen Size Calculator for PPI, Physical Dimensions, Pixel Pitch, and PPD: FAQ
How is PPI calculated?+
PPI is the diagonal pixel count divided by the physical diagonal in inches.
Is advertised diagonal the same as visible panel size?+
Usually it refers to the panel diagonal, but bezels are not included. Exact active-area dimensions can differ slightly by model.
What is pixel pitch?+
Pixel pitch is the physical distance represented by one pixel. It is approximately 25.4 divided by PPI in millimeters.
What are pixels per degree?+
Pixels per degree estimates angular pixel density at a chosen viewing distance. It is useful for comparing how dense a display appears from where you sit.
Does devicePixelRatio affect physical PPI?+
No. Browser devicePixelRatio is a software scaling ratio. Physical PPI comes from hardware resolution and physical panel size.
Use the result responsibly
This tool reports what a browser can observe or calculate in the current environment. Firmware, drivers, operating-system processing, permissions, transport, display timing, audio hardware, device design, and browser implementation can add behavior that this page cannot isolate.
External technical reference: MDN: Screen ↗.