The calculation, without hidden assumptions
A diagonal measurement hides the shape of a screen. A 34-inch ultrawide and a 34-inch 16:9 display have the same diagonal but very different widths and heights. This calculator solves the physical dimensions from the diagonal and aspect ratio instead of assuming every screen is 16:9.
How to use this calculator
Enter the advertised or measured diagonal in inches.
Choose a common aspect ratio or enter the ratio numbers directly.
Read physical width, height, area and perimeter, then compare another ratio without changing the diagonal.
Where people use it
- •TV and monitor fit checks
- •Desk, wall and cabinet planning
- •Comparing ultrawide and standard displays
Example: 55-inch 16:9 display
Using a 16:9 ratio, a 55-inch diagonal produces a screen roughly 47.94 inches wide and 26.96 inches high before bezel dimensions are added.
What the result does not assume
- •The calculation describes the active rectangle, not bezel, stand, wall mount or chassis dimensions.
- •Manufacturers may round the advertised diagonal; use the product drawing for installation clearances.
Frequently asked questions
Why is a 55-inch TV not 55 inches wide?+
The 55-inch specification is the corner-to-corner diagonal, not the horizontal width.
Does aspect ratio change physical dimensions?+
Yes. For the same diagonal, a wider aspect ratio increases width and reduces height.
Does this include the bezel?+
No. Add manufacturer chassis dimensions when checking a physical fit.
Semantic next steps
Continue the calculation
These links move to a different input, formula or project stage rather than a keyword variation of this page.
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OpenFree publisher widget
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Keep the result connected to the real job
MAXScanner keeps the formula and assumptions beside the result so you can verify the number before using it in a drawing, estimate, specification, worksheet or document. Where a supplier, manufacturer, drawing or applicable standard owns a requirement, that source remains authoritative.