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Screen Size Comparison

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

What you provide

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

How this calculation works

A diagonal on its own is not comparable across aspect ratios, and that is the whole reason this calculator exists. The diagonal is split into width and height using the ratio, then the two screens are compared on the dimensions that matter: area, width and height. The result flags the case people regret — a larger diagonal that is a shorter screen, which is what happens moving from 16:9 to an ultrawide. Area is worth watching too, because it grows with the square of the diagonal: a 10% bigger diagonal is a little over 20% more screen.

What the results mean

Screen area
The honest size comparison. It grows with the square of the diagonal, so the percentage is always larger than the difference in inches suggests.
Height difference
The dimension that runs out first for documents, code and spreadsheets. A negative number against a bigger diagonal means the wider screen shows fewer lines of text.
Width difference
What an ultrawide buys you: side-by-side windows and a wider view in games that support the ratio.
Aspect ratio
Given as width:height. 16:9 is standard, 16:10 is slightly taller, 21:9 and 32:9 are ultrawide and considerably shorter at the same diagonal.

Common problems and fixes

My new bigger monitor feels smaller
Compare the heights. Moving from 16:9 to 21:9 at a larger diagonal usually loses height, and height is what you notice in documents and code.
Is one 34-inch ultrawide the same as two 24-inch monitors?
Close in width, but not in area, and one panel has no bezel down the middle. Compare a 34-inch 21:9 against a 24-inch 16:9 here, then double the second area.
The TV I measured is smaller than advertised
Televisions are sold by the panel diagonal, excluding the bezel, and curved screens are quoted along the curve. Both make a tape measure disagree with the box.

Frequently asked questions

Is a 34-inch ultrawide bigger than a 27-inch monitor?

In area yes, in height barely. A 34-inch 21:9 panel is about 31.3 inches wide and 13.4 inches tall; a 27-inch 16:9 is about 23.5 by 13.2. So the ultrawide adds around 7.7 inches of width and about a sixth of an inch of height. If you want more lines of text rather than more windows side by side, the extra seven inches of diagonal buy you almost nothing.

How much bigger is a 32-inch than a 27-inch monitor?

At the same 16:9 ratio, about 40% more screen area — the diagonal is 18.5% larger and area grows with the square. In dimensions that is roughly 27.9 by 15.7 inches against 23.5 by 13.2. It is a much bigger jump than the two numbers suggest.

Why are screens measured diagonally?

Convention, from early television, where a single number was easier to market than two. It only compares like with like: at the same aspect ratio a bigger diagonal is a bigger screen, but across ratios it can mean wider and shorter, larger in area but smaller in height, or almost anything else. Width, height and area are the comparison that survives a change of ratio.

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