Screen Size Comparison
Two displays drawn to true relative scale. Diagonal figures hide how much difference a few inches — or a change of aspect ratio — really makes.
Screen A
- Size
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- Area
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- Density
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Screen B
- Size
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- Area
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- Density
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Why diagonals mislead
Screen size is sold as a single diagonal number, but area — the thing you actually gain — grows with the square of that number. Going from 24 to 27 inches sounds like a 12.5% increase. In 16:9 it is about 27% more screen area. That is why the step up feels bigger in person than the specification suggests.
The same maths works against you at the top end: 32 to 34 inches is only about 13% more area, which is far less than the price difference usually implies.
Aspect ratio changes everything
Two screens with an identical diagonal but different shapes are not the same size. Spreading a fixed diagonal wider makes it shorter — so a 34-inch 21:9 ultra-wide is shorter than a 27-inch 16:9 monitor, despite the much larger number on the box. Anyone moving to ultra-wide for the first time notices the lost vertical space immediately.
Size against sharpness
| Size & resolution | Density | How it reads at a desk |
|---|---|---|
| 24″ 1080p | ~92 PPI | The comfortable baseline |
| 27″ 1080p | ~82 PPI | Noticeably soft — avoid |
| 27″ 1440p | ~109 PPI | The sweet spot for most desks |
| 32″ 1080p | ~69 PPI | Individual pixels visible |
| 32″ 4K | ~138 PPI | Sharp; wants OS scaling |
| 34″ 21:9 1440p | ~110 PPI | Wide, but shorter than a 27″ |
The pattern is simple: size and resolution have to rise together. A bigger panel at the same resolution buys you room at the cost of sharpness.
Getting your own numbers
"Use my screen" fills side A from this device, using your saved bank-card calibration if you have one — otherwise it is an estimate and the monitor size tool will tell you which. To work out ratios for an unfamiliar resolution, use the aspect ratio calculator.
More screen tools
Screen Resolution
Detect your display resolution, pixel ratio and viewport instantly.
Full Monitor Test New
Run every display check in one guided sequence and get a summary.
Monitor Size
Work out your physical screen size in inches from its resolution and DPI.
Online Ruler
A calibrated ruler in actual size — cm, mm, inches or pixels.
FPS Test New
Live frame rate, 1% lows and stutter, with a frame-time graph.
Refresh Rate Test New
Measure the true refresh rate of your display in Hz, live.
Dead Pixel Test New
Fullscreen solid colours that expose dead, stuck and hot pixels.
Screen Colour Test New
Check colour accuracy, gradients, banding and panel uniformity.
Aspect Ratio Calculator New
Work out and resize any aspect ratio, with a live to-scale preview.
Burn-in Test New
Check OLED and LCD panels for image retention, and try to clear it.
Touch Screen Test New
Find dead zones and check multi-touch by drawing on the screen.
Backlight Bleed Test New
Find light leaking around the edges of an LCD panel.
Ghosting Test New
Check motion blur, trailing and pixel response with moving objects.
Frequently asked questions
How much bigger is a 27-inch monitor than a 24-inch?
At the same 16:9 ratio, about 27% more screen area — not 12.5% as the diagonal figures suggest. Area grows with the square of the diagonal, which is why the jump feels larger in person than the numbers imply. The comparison above shows both drawn to scale.
Why is my ultra-wide shorter than my old monitor?
Because diagonal size is quoted regardless of shape. A 34-inch 21:9 screen spreads the same diagonal much further sideways, so it ends up shorter than a 27-inch 16:9. People upgrading to ultra-wide are often surprised to lose vertical space. Set both sides above and you will see it.
Does a bigger screen mean a worse picture?
It can. Stretching the same resolution over a larger panel lowers pixel density, so text gets coarser. A 32-inch 1080p monitor is about 69 PPI and looks noticeably soft at desk distance; a 24-inch 1080p is about 92 PPI and looks fine. The comparison shows PPI for both so you can check.
What size monitor should I buy?
For a normal desk at arm's length, 24 to 27 inches suits most people, with 27-inch paired with 1440p rather than 1080p. Beyond 32 inches you start moving your head rather than your eyes, and you want 4K to keep the density up. Ultra-wide is worth it if you work in wide timelines or many side-by-side windows.
How do I measure my current screen to compare?
Measure the panel corner to corner, ignoring the bezel — that is the figure manufacturers quote. Or press "Use my screen" and it fills in what this device reports, using your saved calibration if you have set one.
Is screen area the number that matters?
It is the honest one for "how much bigger", but pair it with pixel density. A large screen with low density gives you more space and coarser text; a smaller dense screen gives sharper text with less room. Both figures are shown for each side.