Trust & transparency

How screen measurements are calculated.

Every derived number follows a published formula. Every named-device specification links to a primary source when one is available.

Last reviewed:

01 · Sources

Primary sources first

Named-device diagonals, resolutions, and stated pixel densities come from official manufacturer technical specifications wherever possible. Each record stores its source link and review date. Representative size classes—such as a generic 65-inch 4K TV—are explicitly labeled as illustrative rather than attached to a particular model.

When a source gives a nominal diagonal and a standard-rectangle diagonal, calculations use the more precise standard-rectangle value and retain the nominal label for context. Rounded corners and cutouts mean actual viewable area can be smaller.

02 · Geometry

Calculation formulas

In Physical dimensions mode, user-entered width and height define the active display rectangle; bezels, stands, and the device body are excluded. The tool derives diagonal, long-to-short aspect ratio, area, and orientation. In Screen specifications mode, diagonal and aspect ratio define the rectangle, and the tool derives width, height, and area.

Physical width

width = diagonal × aspectWidth ÷ √(aspectWidth² + aspectHeight²)

Physical height

height = diagonal × aspectHeight ÷ √(aspectWidth² + aspectHeight²)

Diagonal from physical dimensions

diagonal = √(width² + height²)

Aspect ratio from physical dimensions

aspect ratio = longer side : shorter side

Screen area

area = width × height

Pixel density

PPI = √(horizontalPixels² + verticalPixels²) ÷ diagonalInches

Percentage increase

increase % = (largerValue ÷ smallerValue − 1) × 100

03 · Provenance

What the evidence labels mean

Official
Directly stated by a linked manufacturer source.
Calculated
Derived from official or explicitly listed inputs using the formulas above.
Illustrative
A clearly named size-class assumption, not a claim about one product.

These labels describe records in the published dataset. Values entered into the interactive tool are unsourced user inputs and are not added to that evidence model or presented as manufacturer claims.

04 · Precision

Rounding without false precision

Calculations retain full precision internally. The interface generally shows physical dimensions to 2 decimal places, percentage differences to 1 decimal place, and PPI to the nearest whole number. A leading ≈ identifies an equivalent diagonal derived from a published display area. The selected input mode explains whether the live rectangle begins with entered dimensions or with screen specifications.

05 · Limitations

What the model does not assume

  • Screen rectangles do not include bezels, stands, hinges, or product bodies.
  • Rounded displays are visualized as their standard rectangle unless a source provides usable-area geometry.
  • PPI does not measure brightness, contrast, color, response time, refresh rate, or overall panel quality.
  • The browser visualization is proportionally accurate between selected screens, not physically calibrated to your current display.
  • Cinema and projected-image sizes vary by venue and setup; illustrative entries are named as such.

Found a specification that needs correction? Use the linked primary source to verify it, then share the exact record and source with the site owner.