The monitor size calculator converts a monitor's diagonal size to physical width and height, and calculates pixel density (PPI) for any resolution. Use this to compare monitors, plan your desk setup, or verify a monitor will fit your space.
Calculate Monitor Dimensions
Common Monitor Sizes (16:9)
| Size | Width | Height | 1440p PPI |
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Monitor Size and PPI Guide
The monitor size calculator helps you understand exactly how large a monitor is and how sharp its image will be. Screen diagonal is just one dimension — actual width and height determine if it fits on your desk or wall.
Pixels Per Inch (PPI) Explained
PPI = pixels per inch = pixel density. Calculated as the diagonal pixel count divided by the physical diagonal in inches. A 27" 1440p monitor has 2915 diagonal pixels ÷ 27 inches = 108 PPI. At typical 60cm viewing distance, 90-110 PPI is acceptable, 110-140 is good, 140+ is sharp. Apple's "retina" threshold is about 220 PPI at arm's length.
Choosing Between 24" and 27"
At 1080p: 24" gives 92 PPI (sharper), 27" gives 82 PPI (slightly soft up close). At 1440p: 27" gives 109 PPI (excellent sweet spot). At 4K: 24" gives 184 PPI (very sharp, may need scaling), 27" gives 163 PPI (great without scaling). Most professionals use 27" 1440p as the best value and ergonomics combination.
Frequently Asked Questions
Is this monitor size calculator free?
Yes, completely free with no signup required. Calculate monitor dimensions and pixel density for any screen size.
What are the dimensions of a 27-inch monitor?
A standard 27-inch 16:9 monitor is approximately 23.5 inches wide and 13.2 inches tall (59.7 × 33.5 cm). A 27-inch 21:9 ultrawide is about 25 inches wide and 10.6 inches tall.
What is a good PPI for a monitor?
For desktop monitors at typical viewing distances (50-75 cm): 90-110 PPI looks okay; 110-140 PPI is good; 140-180 PPI is sharp (like most 27" 1440p monitors at 108 PPI); 180+ PPI approaches 'retina' territory where individual pixels are invisible. 4K at 27 inches is about 163 PPI.
How far should I sit from a 27-inch monitor?
For a 27-inch 1440p monitor: 50-80 cm (20-31 inches) is the recommended distance. Closer means more immersion and the ability to see fine details; farther reduces eye strain for those who work long hours. 60 cm (24 inches) is a common sweet spot.
Is 24 or 27 inches better for a monitor?
For 1080p resolution: 24 inches provides a sharper image (94 PPI vs 82 PPI at 27"). For 1440p: 27 inches is the sweet spot (108 PPI). For 4K at 24 inches: 183 PPI is excellent but text may need scaling. Most professional users choose 27" 1440p as the best balance.