Screen Size Comparison
Compare two screens drawn at the same physical scale, to see how much bigger one really is.
Screen A
A screen’s advertised size is its diagonal, corner to corner. Its aspect ratio — 16:9 standard widescreen, 21:9 ultrawide — decides how that diagonal is split between width and height, so two screens of the same size can be very different shapes.
Common diagonals
Common aspect ratios
Add screen resolution optional
Optional — add the screen resolution if you also want pixel-density information for this screen.
Screen B
Common diagonals
Common aspect ratios
Add screen resolution optional
Optional — add the screen resolution if you also want pixel-density information for this screen.
Display area, Screen B against Screen A
+34.4%
Screen B has 34.4% more display area than Screen A. It is 32.8% wider and 1.2% taller.
Screen B has 34.4% more display area than Screen A.
Relative size
Screen A
- Width23.53 in
- Height13.24 in
- Area311.5 in²
- Diagonal27 in
Screen B
- Width31.25 in
- Height13.39 in
- Area418.55 in²
- Diagonal34 in
Difference, B relative to A
- Width+32.8%7.72 in
- Height+1.2%0.16 in
- Area+34.4%107.05 in²
- Diagonal+25.9%7 in
Formula and assumptions
For each screen with diagonal D and aspect ratio A : B
scaleequalsD ÷ √(A² + B²)
widthequalsA × scale
heightequalsB × scale
areaequalswidth × height
Comparing Screen B with Screen A
differencePercentequals((B − A) ÷ A) × 100
Applied separately to width, height, area and diagonal.
Assumptions
- Every percentage describes Screen B relative to Screen A.
- Screen size means the diagonal of the active display area. Bezels, stands and curvature are not modelled.
- When the two screens are entered in different units, both are converted to inches before comparison, using 1 inch = 25.4 mm exactly.
- Pixel density figures appear only for a screen whose resolution you supply.
Questions
Why is a 34-inch ultrawide not much bigger than a 27-inch 16:9 screen?
Diagonal length grows with both width and height. An ultrawide spends most of its extra diagonal on width while losing height, so the gain in total display area is smaller than the difference in diagonals suggests.
What does the percentage refer to?
Every percentage describes Screen B relative to Screen A. A width difference of +18.4% means Screen B is 18.4% wider than Screen A. Use Swap A and B to reverse the reference.
Are the two screens drawn to the same scale?
Yes. Both are drawn in one shared coordinate system on a common baseline, so their relative sizes are accurate. Neither is shown at real physical size, because a browser cannot know the dimensions of your display.
Do I need to enter resolutions?
No. Resolutions are optional and only used to calculate pixel density and megapixels. Physical size comparison needs only a diagonal and an aspect ratio.