What this tool does
See how aspect ratio changes the usable width and height of screens with the same advertised diagonal.
How to use it
- Enter the diagonal screen size in inches.
- Enter the aspect-ratio width and height.
- Optionally enter resolution to calculate pixel density.
Formula and method
Ratio diagonal = √(ratio width² + ratio height²). Physical width and height scale each ratio side to the diagonal. PPI divides diagonal pixels by diagonal inches.
Example
A 27-inch 16:9 display is about 59.77×33.62cm. At 2560×1440 it is about 108.79 PPI.
Useful for
- Checking whether a monitor fits a desk
- Comparing TV and laptop dimensions
- Comparing resolution and pixel density
Limits and notes
Results describe the display area, not bezels or stands. Manufacturer rounding can cause small differences.
Frequently asked questions
Is the advertised size the width?
No. It is the diagonal of the viewable area.
Is resolution required?
No. Width and height still calculate; only PPI is omitted.