Screen Size Comparison

Compare two screens by area, width and height — not by the diagonal they are sold on.

What you provide

Screen A diagonal(in)

Screen A ratio

Screen B diagonal(in)

Screen B ratio

Result

B has 34% more screen area

Different aspect ratios, so the diagonals are not comparable directly. By area — the honest comparison — B is 34% larger, 7.7 in wider and 0.2 in taller.

Diagnostic telemetry

A — 27" 16:9312 sq in: 23.5 × 13.2 in
B — 34" 21:9419 sq in: 31.3 × 13.4 in
Screen areaB compared with A: +34.4%
Width difference: +7.7 in
Height difference: +0.2 in

What this cannot tell you

Compares the panel itself, from the diagonal and the aspect ratio. Bezels, stands and the overall footprint of the monitor are not included and vary widely between models.
Assumes the diagonal is measured flat, corner to corner. A curved screen quoted along its curve is slightly smaller in a straight line than the number suggests.
Says nothing about resolution or pixel density. Two screens of identical area can differ completely in sharpness — the PPI calculator is the tool for that.
Desk space is not screen area. A wider screen may not fit where a taller one does, and neither figure here accounts for how far away you can sit.

Take this with you

Screen Size Comparison on RunTheTests — free browser-based device tools, no sign-up.