Screen Resolution Calculator
NewCalculate aspect ratio, total megapixels, and pixels-per-inch (PPI) from a screen resolution and physical diagonal size, with common resolution name lookup.
aspect ratio
megapixels
PPI
common name
Frequently Asked Questions
How is PPI (pixels per inch) calculated?
The diagonal resolution in pixels (computed from width and height using the Pythagorean theorem) is divided by the physical diagonal screen size in inches — giving pixel density, which is why a phone screen has much higher PPI than a large TV at the same resolution.
Why does the aspect ratio show as something like 16:9 instead of the raw pixel numbers?
The tool reduces the width and height to their simplest ratio using the greatest common divisor — so 1920×1080 simplifies to 16:9, the standard widescreen ratio, rather than showing the unreduced pixel counts.
What if my exact resolution isn't in the "common name" list?
The common-name lookup only covers well-known standard resolutions (HD, Full HD, QHD, 4K UHD, and similar) — many resolutions (especially ultrawide or unusual custom resolutions) simply won't have a common marketing name and will show as "—".
Is the diagonal size field required?
No — it's optional and only needed to calculate PPI. Aspect ratio and total megapixels are calculated from the resolution alone and will show regardless of whether a diagonal size is entered.