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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Put this calculator on your website
Give readers the live calculator without rebuilding the math. Copy the responsive embed in one click, or customize width, height, border and corner radius before publishing. The branded MAXScanner attribution stays visible.
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.