Screen Dimensions Calculator

Calculate physical screen width and height from diagonal size and aspect ratio.

How to use Screen Dimensions Calculator

1. Enter Diagonal Size, Aspect Ratio Width, Aspect Ratio Height, Size Unit. 2. Choose inches, cm or mm and use that same unit for every physical screen dimension. Results keep the selected unit. The active screen is an ideal rectangle; bezels and curved-screen geometry are excluded. 3. Select Calculate or press Enter. 4. Select Copy result to copy the answer, or Reset to clear the form and result.

Why use this tool?

Choose inches, cm or mm and use that same unit for every physical screen dimension. Results keep the selected unit. The active screen is an ideal rectangle; bezels and curved-screen geometry are excluded.

How the calculation works

Scale width:height so square root(width² + height²) equals the entered diagonal. Choose inches, cm or mm and use that same unit for every physical screen dimension. Results keep the selected unit. The active screen is an ideal rectangle; bezels and curved-screen geometry are excluded. Counts and dimensions use the declared rounding convention; other numbers display up to three decimal places where applicable. Nonzero subsecond durations are labelled. Durations round to the nearest second; nonzero subsecond durations are labelled. File-size output units are decimal. Changing an input label does not convert filled values.

Example

Worked example: Diagonal Size = 5; Aspect Ratio Width = 3; Aspect Ratio Height = 4; Size Unit = "inches". Result: 3 × 4 in.

Practical tip

Check the input labels and assumptions against the screen dimensions task before reusing the number.