Formula
The diagonal is the hypotenuse:
inches = √(width² + height²)
The screen PPI page divides a pixel diagonal by a size you type. This page produces the size from the two sides.
Assumptions
- Width and height are the visible image, in inches.
- The corners are square.
- The bezel is not included.
Worked example
A 12 by 9 inch image has a diagonal of 15 in.
Input definitions
- Width
- The horizontal measure of the lit area.
- Height
- The vertical measure of the same area.
Limitations
This is a planning figure from the numbers you type. It is not a measurement of a network, a camera, a printer, or a power supply.
Questions
Why not enter the advertised size?
The advertised size is this diagonal. Enter it on the PPI page when you already know it.
Does 12 by 9 have to be a monitor?
No. Any rectangular image area uses the same hypotenuse.