Screen Size Calculator

Calculate display dimensions, PPI, aspect ratio, and viewable area from diagonal size and resolution. Compare monitors, TVs, tablets, and phones.

PPI
108.79
Pixel size: 0.233 mm
Width
23.53"
59.8 cm
Height
13.24"
33.6 cm
Area
311.5 sq in
2,010 cm²
Aspect Ratio
16:9
1.78:1
Megapixels
3.69 MP
3,686,400 px
Opt. Viewing Dist.
31.6"
80 cm (1 px < 1 arcmin)

Size Visualization

23.5" × 13.2"
Your Display

Display Comparison

DisplaySizePPIArea (sq in)MP
24" 1080p20.9" × 11.8"922462.1
27" 1440p23.5" × 13.2"1093123.7
27" 4K23.5" × 13.2"1633128.3
32" 4K27.9" × 15.7"1384388.3
34" UW 1440p31.4" × 13.1"1104125.0
49" SUW 1440p47.2" × 13.3"1096267.4
55" 4K TV47.9" × 27.0"801,2938.3
65" 4K TV56.7" × 31.9"681,8058.3
14" Laptop 1080p12.2" × 6.9"157842.1
iPhone 15 Pro2.6" × 5.5"461143.0
iPad Pro 12.9"7.7" × 10.3"265805.6
PPI Sharpness Reference
PPI RangeAt 24"At Arms LengthTypical Use
< 80PixelatedClearly visible pixelsLarge TVs from distance
80-110AdequateMinor pixel visibilityStandard desktop monitors
110-150SharpPixels barely visibleHigh-res desktop monitors
150-220Very SharpRetina-quality4K monitors, laptops
220+FlawlessIndistinguishableRetina laptops, phones
Planning notes, formulas, and examples

About the Screen Size Calculator

The Screen Size Calculator converts a display's diagonal measurement and resolution into exact width, height, area, PPI (pixels per inch), and pixel density metrics. Enter any screen's diagonal and resolution to see its precise physical dimensions and how it compares to other displays.

Manufacturers advertise screen size as the diagonal measurement, but two 27-inch monitors can feel very different depending on their aspect ratio. A 27" 16:9 display is 23.5" wide and 13.2" tall, while a 27" 21:9 ultrawide is 25.1" wide but only 10.7" tall — nearly 20% less vertical space.

This calculator reveals the hidden dimensions, computes pixels per inch to gauge sharpness, and compares multiple displays side by side. It also calculates optimal viewing distance based on visual acuity and resolution, helping you decide between a 27" 1440p and a 32" 4K monitor. Try a monitor, TV, or phone you already use to compare its physical size against the sharpness you expect.

When This Page Helps

Understand exact physical dimensions, sharpness, and optimal viewing distance for any display. Helpful when choosing between monitors, TVs, and mobile devices or planning desk, living-room, and portable viewing setups.

How to Use the Inputs

  1. Enter the screen diagonal in inches.
  2. Enter the horizontal and vertical resolution in pixels.
  3. View physical width, height, area, PPI, and pixel density.
  4. Use presets for common monitors, TVs, and mobile devices.
  5. Compare against the reference table of popular displays.
  6. Check the recommended viewing distance for your screen.
Formula used
Width = Diagonal × cos(atan(V_res / H_res)). Height = Diagonal × sin(atan(V_res / H_res)). PPI = √(H_res² + V_res²) / Diagonal. Area = Width × Height.

Example Calculation

Result: 23.53" × 13.24", 108.79 PPI, 311.5 sq in

A 27" 16:9 display at 2560×1440 has PPI of 108.79. The physical width is 23.53 inches and height is 13.24 inches, with a total viewable area of 311.5 square inches.

Tips & Best Practices

  • For coding/text work, prioritize PPI over screen size — 109+ PPI makes text crisp.
  • Ultrawide monitors add horizontal space but NOT vertical; compare the height carefully.
  • TV screen sizes have grown faster than living room sizes — check viewing distance recommendations.
  • Dual 24" monitors provide more total area than a single 32" at the same resolution.
  • OLED screens measure the full panel; LCD panels lose ~3-5mm to bezels on each side.

Understanding PPI and Pixel Density

PPI (Pixels Per Inch) measures how tightly pixels are packed. Higher PPI means sharper text, smoother curves, and less visible pixel grid. The PPI formula uses the Pythagorean theorem on the resolution to find the diagonal pixel count, then divides by the physical diagonal.

At 96 PPI (a "standard" Windows DPI), pixels are about 0.265mm wide — easily visible from arm's length. At 220 PPI (MacBook Retina), pixels are 0.115mm — invisible to most eyes at laptop distance. At 460 PPI (modern phones), individual pixels require a magnifying glass to see.

Aspect Ratios in Practice

The 16:9 (1.78:1) ratio dominates consumer displays because it balances widescreen media consumption with productivity. For ultrawide productivity, 21:9 (2.33:1) provides ~33% more horizontal space. For cinema buffs, 32:9 (3.56:1) displays approximate two 16:9 screens edge-to-edge.

Vertical monitors (rotated 16:9) provide excellent code/document viewing at 9:16 — 1440×2560 offers tremendous vertical scroll space for reading and development work.

Viewing Distance Science

The human eye can resolve about 1 arcminute of detail. This means pixel size (in arcminutes at viewing distance) determines whether resolution matters. At 3 feet from a 27" 1080p (82 PPI), each pixel subtends ~1.6 arcminutes — clearly resolvable. At 10 feet from a 65" 4K TV (68 PPI), each pixel subtends ~0.5 arcminutes — invisible. This is why huge 4K TVs look sharp across the room but small 1080p monitors look grainy up close.

Sources & Methodology

Last updated:

Frequently Asked Questions

  • Apple defines Retina as PPI where individual pixels are not discernible at typical viewing distance. For laptops (~18"), that's ~220+ PPI. For desktop monitors (~24"), ~110+ PPI. For phones (~12"), ~300+ PPI.