Display size calculator

Find rectangular screen dimensions from diagonal and aspect ratio using the Pythagorean theorem.

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Diagonal length

Aspect width

More inputs and assumptions

Aspect height

Answer

…

Find rectangular screen dimensions from diagonal and aspect ratio using the Pythagorean theorem.

More results

Precision and calculation record

Decimal places in numeric results and text downloads

Rounding changes displayed numbers, not the calculation. Text, fractions, matrices and CSV schedules keep their own formatting. Automatic keeps up to 12 significant digits, with money shown to cents where applicable.

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Formula and assumptions

Width = diagonal × aspect width/√(aspect width² + aspect height²); height follows the same rule. Excludes bezel and stand; curved screens need manufacturer dimensions.

Automatic precision shows numbers to 12 significant digits. Thousands separators such as 1,000 are accepted; use a dot for decimals.

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Updated 2026-09-26

Using Display size calculator

Find rectangular screen dimensions from diagonal and aspect ratio using the Pythagorean theorem.

Width = diagonal × aspect width/√(aspect width² + aspect height²); height follows the same rule. Excludes bezel and stand; curved screens need manufacturer dimensions.

Next: Calculate ppi

A worked example

Example inputs: diagonal length = 5, aspect width = 4, aspect height = 3. Screen width = 4.

Before you use the result

Width = diagonal × aspect width/√(aspect width² + aspect height²); height follows the same rule. Excludes bezel and stand; curved screens need manufacturer dimensions.

Example results for diagonal length

These examples use Aspect width: 4; Aspect height: 3. They are reference calculations, not recommended settings.

Diagonal length	Screen width
2.5	2
5	4
10	8

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