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Monitor size comparison: see screen sizes to scale
Quick answer: monitor size is the screen’s diagonal, so a 16:9 27-inch screen is about 23.5 × 13.2 inches and has 27% more area than a 24-inch (20.9 × 11.8 in). A 34-inch ultrawide is the same height as a 27-inch, just 8 inches wider. Pick two or three monitors below to see them to scale on your desk.
By WFH Lounge editorial team · Updated
Monitor B (27" 16:9) has 27% more screen area than Monitor A (24" 16:9): it is 2.6 in wider and 1.5 in taller, with 109 vs 92 pixels per inch.
What size is my monitor?
A web page can read your screen’s resolution but not its size in inches, so this takes one ruler measurement. Runs in your browser; nothing is uploaded.
Reading your screen…
- Set your browser zoom to 100% and keep this window on the monitor you want to measure.
- Hold a ruler or tape measure against the screen and measure the pink bar end to end.
- Type what you measured. The diagonal appears instantly.
Monitor sizes chart: width, height and area
Screen dimensions for the common monitor sizes, worked out from each diagonal and native resolution. These are the picture area only; the monitor itself is wider by its bezels.
| Size | Resolution | Aspect | Width × height | Area | PPI |
|---|---|---|---|---|---|
| 21.5″ | 1920×1080 | 16:9 | 18.7 × 10.5 in47.6 × 26.8 cm | 198 sq in | 102 |
| 24″ | 1920×1080 | 16:9 | 20.9 × 11.8 in53.1 × 29.9 cm | 246 sq in | 92 |
| 24″ | 1920×1200 | 16:10 | 20.4 × 12.7 in51.7 × 32.3 cm | 259 sq in | 94 |
| 27″ | 2560×1440 | 16:9 | 23.5 × 13.2 in59.8 × 33.6 cm | 312 sq in | 109 |
| 27″ | 3840×2160 | 16:9 | 23.5 × 13.2 in59.8 × 33.6 cm | 312 sq in | 163 |
| 32″ | 3840×2160 | 16:9 | 27.9 × 15.7 in70.8 × 39.8 cm | 438 sq in | 138 |
| 34″ | 2560×1080 | 21:9 class (64:27) | 31.3 × 13.2 in79.6 × 33.6 cm | 414 sq in | 82 |
| 34″ | 3440×1440 | 21:9 class (43:18) | 31.4 × 13.1 in79.7 × 33.3 cm | 412 sq in | 110 |
| 38″ | 3840×1600 | 21:9 class (12:5) | 35.1 × 14.6 in89.1 × 37.1 cm | 513 sq in | 109 |
| 40″ | 5120×2160 | 21:9 class (64:27) | 36.9 × 15.5 in93.6 × 39.5 cm | 573 sq in | 139 |
| 43″ | 3840×2160 | 16:9 | 37.5 × 21.1 in95.2 × 53.5 cm | 790 sq in | 102 |
| 49″ | 5120×1440 | 32:9 | 47.2 × 13.3 in119.8 × 33.7 cm | 626 sq in | 109 |
Pixel density by size and resolution
Pixels per inch (PPI) is how many pixels sit along one inch of the screen. The same resolution on a bigger screen means bigger pixels and lower PPI, which is why 1080p looks soft on a 27-inch screen and 4K at 27 inches looks crisp.
| Size | 1080p (Full HD) | 1440p (QHD) | 4K UHD |
|---|---|---|---|
| 21.5″ | 102 PPI | 137 PPI | 205 PPI |
| 24″ | 92 PPI | 122 PPI | 184 PPI |
| 27″ | 82 PPI | 109 PPI | 163 PPI |
| 32″ | 69 PPI | 92 PPI | 138 PPI |
Advertised size vs certified size
Monitor sizes are sold rounded, and some are “class” sizes. These are the screen sizes and areas the makers certified to ENERGY STAR for monitors we rank, from EPA’s public dataset.
| Monitor | Sold as | Certified size | Certified area | Resolution |
|---|---|---|---|---|
| Dell S2725QC | 27" | 27 in | 310.5 sq in | 3840×2160 |
| Dell UltraSharp U2725QE | 27" | 27 in | 310.47 sq in | 3840×2160 |
| Dell 27 Plus S2725DSM | 27" | 27 in | 310.47 sq in | 2560×1440 |
| ASUS ProArt PA279CDV | 27"-class | 26.5 in | 300.95 sq in | 3840×2160 |
| Dell UltraSharp U3225QE | 32" | 31.5 in | 423.94 sq in | 3840×2160 |
| Dell S3425DW | 34" | 34 in | 412.4 sq in | 3440×1440 |
| Dell UltraSharp U3425WE | 34" | 34.1 in | 415.09 sq in | 3440×1440 |
How to measure monitor size
- Turn the screen on with a bright image, so you can see exactly where the picture ends and the black border begins.
- Measure diagonally from the bottom-left corner of the picture to the top-right corner. Do not include the bezel, the frame or the stand.
- Read it in inches. If your tape is metric, divide centimeters by 2.54. A reading of 68.5 cm is 27 inches.
- Round the way makers do. A 26.5 to 27-inch reading is sold as a 27-inch screen; a 31.5-inch one as a 32-inch.
For the width and height of the whole monitor (to check it fits between shelves or on an arm), use the dimensions on the maker’s spec sheet, which include the bezels.
Choosing a size for your desk
- Viewing distance. OSHA’s workstation guidance puts the preferred viewing distance at 20 to 40 inches (50 to 100 cm) from eye to screen, and notes that text may need to be larger on smaller monitors. A shallow desk favors a smaller screen or a monitor arm that pushes it back.
- Width. Two 27-inch screens need about 47 inches of panel width plus their bezels, so they fill most of a 48-inch desk. The drawing above shows how much room is left on yours.
- Height. 27-inch 16:9, 34-inch ultrawide and 49-inch super ultrawide screens are all about 13 inches tall. A 32-inch 16:9 screen is about 2.5 inches taller than a 27-inch, so the top edge sits higher; check it against the monitor height from our ergonomic setup calculator.
- Sharpness. Bigger is only better if the resolution keeps up: compare PPI in the tool, not just inches.
How this monitor size comparison works
A flat screen’s width, height and diagonal form a right triangle, and monitors have square pixels, so the native resolution sets the shape. For a diagonal D and a resolution of W × H pixels, the pixel diagonal is √(W² + H²); width = D × W / √(W² + H²), height = D × H / √(W² + H²), and PPI = √(W² + H²) / D. Pixel pitch is 25.4 mm divided by PPI. The drawing uses the same inches for every screen and for the desk, so it is to scale; stands are drawn only as a guide.
The “what size is my monitor” finder reads your screen’s width and height in CSS pixels and the device pixel ratio, which together give the native resolution. A browser can’t know physical size: on screens, a CSS inch is defined as 96 CSS pixels, not a real inch (W3C). So the page draws a bar of known CSS-pixel length, you measure it, and the diagonal is the screen’s CSS-pixel diagonal divided by the pixels per inch that measurement implies. Browser zoom and display scaling cancel out because both sides are in CSS pixels, but the result is only as good as your ruler.
Picked a size? Monitors we rank in it
One pick per common size from our ranked monitors, scored on manufacturer specs and owner feedback. Sizes and densities come from the tables above.
Weighing two screens against one wide one? Read dual monitors vs an ultrawide, or set a ceiling in the budget finder.
Monitor size FAQ
How do you measure monitor size?
Measure the screen diagonally, from one corner of the lit picture area to the opposite corner, leaving out the bezel and stand. That diagonal in inches is the size a monitor is sold by; to get centimeters, multiply by 2.54.
What size is my monitor?
Check the model number on the label on the back and look up its spec sheet, or measure the picture diagonally with a tape. The finder on this page does it with one ruler reading: it reads your screen's resolution and turns your measurement of an on-screen bar into the diagonal.
How much bigger is a 27-inch monitor than a 24-inch?
With the same 16:9 shape, a 27-inch screen is about 2.6 inches wider and 1.5 inches taller than a 24-inch and has about 27% more screen area, because area grows with the square of the diagonal.
Is a 34-inch ultrawide bigger than a 27-inch monitor?
It is wider, not taller. A 34-inch 3440×1440 ultrawide is about 31.4 inches wide and 13.1 inches tall, while a 27-inch 16:9 screen is about 23.5 by 13.2 inches. You gain roughly 8 inches of width and about a third more area at the same height.
Is a 49-inch super ultrawide the same as two 27-inch monitors?
Almost exactly. A 49-inch 32:9 panel works out to about 47.2 by 13.3 inches, and two 27-inch 16:9 panels side by side are about 47.1 by 13.2 inches, without the bezels in the middle. Both are 5120 pixels wide in total when the 27s are 1440p.
Does monitor size include the bezel?
No. The advertised diagonal covers the picture area only, and it is often rounded: ENERGY STAR's certification data lists ASUS's "27-inch" ProArt PA279CDV at 26.5 inches and Dell's "32-inch" U3225QE at 31.5 inches. Check the spec sheet's dimensions for the full width with bezels.
Sources
- U.S. EPA, ENERGY STAR: ENERGY STAR Certified Displays (dataset qbg3-d468) — Certified screen size, screen area and native resolution for seven monitors we rank, including the "27-inch" ASUS PA279CDV at 26.5 in and the "32-inch" Dell U3225QE at 31.5 in.
- OSHA: Computer Workstations eTool: Monitors — The preferred viewing distance of 20 to 40 inches (50 to 100 cm), and the note that text size may need increasing on smaller monitors.
- MDN Web Docs: Window: devicePixelRatio property — The ratio of physical pixels to CSS pixels, used to estimate your screen's native resolution.
- MDN Web Docs: Screen: width property — A page can read the screen's width in CSS pixels, not in inches.
- W3C: CSS Values and Units Module Level 4: absolute lengths — On screens a CSS inch is anchored to the reference pixel (96 px), not to a physical inch, which is why the size finder asks you to measure a bar with a ruler.
- ITU-R: Recommendation ITU-R BT.709: HDTV parameter values — The 1920 × 1080 image format.
- ITU-R: Recommendation ITU-R BT.2020: UHDTV parameter values — The 3840 × 2160 (4K UHD) image format.
Last checked: . Screen dimensions are calculated from diagonal and resolution. WFH Lounge recommendations are researched from manufacturer specs and owner feedback, not hands-on testing.