Screen size detector
Tells you the diagonal inches, resolution and pixel density of the screen you are reading this on. Useful for buying a replacement, picking a docking station, or settling an argument.
How the estimate works (and why it is an estimate)
Browsers do not expose a "physical screen size in millimetres" property — that is by design. So the tool does what a human would do: it takes the resolution your screen reports, looks up the panel sizes that resolution typically ships in, and gives you the closest standard size.
For example: a screen that reports 1920×1080 at a 1× pixel ratio is almost always a 15.6-inch laptop or a 21.5-to-24-inch external monitor. The tool can usually tell which from the aspect ratio and DPR, but for absolute certainty you should still run a tape measure across the visible glass.
Common laptop screen sizes (2026)
| Diagonal | Common resolution | Typical models |
|---|---|---|
| 11.6" | 1366×768 | Older Chromebooks, budget netbooks |
| 13.3" | 1920×1200, 2560×1600 | MacBook Air 13, Dell XPS 13, Asus ZenBook 13 |
| 14" | 1920×1200, 2880×1800 | MacBook Pro 14, ThinkPad X1 Carbon, HP Spectre 14 |
| 15.6" | 1920×1080, 2560×1440 | Most mainstream Windows laptops — HP Pavilion 15, Dell Inspiron 15, Lenovo IdeaPad 5 |
| 16" | 2560×1600, 3456×2234 | MacBook Pro 16, Asus ROG Strix G16 |
| 17.3" | 1920×1080, 2560×1440 | Gaming flagships, mobile workstations |
Measure it manually in 30 seconds
Take any tape measure (cm or inches — both work). Run it from the bottom-left corner of the visible glass to the top-right corner. The black plastic bezel does not count. The number you get is the diagonal — what manufacturers and shops advertise.
If you only have a ruler: measure the width and height in inches, then square them, add them, and take the square root. √(width² + height²) = diagonal. A laptop screen 13.6" wide and 7.65" tall has a diagonal of about 15.6 inches.
Picking a replacement screen by size alone is risky
Even if you know your laptop is 15.6 inches, you cannot just buy any 15.6-inch panel. Replacement panels differ in:
- Connector type — eDP 30-pin, eDP 40-pin, LVDS 30/40-pin. Wrong connector, no picture.
- Mounting points — top/bottom vs left/right brackets. Wrong brackets, panel does not screw in.
- Resolution — a 1920×1080 panel will not work in a laptop wired for 1366×768 (or vice versa).
- Backlight type — touchscreen vs matte vs glossy.
Always look up the original panel's part number (printed on a sticker on the back of the panel itself) and order an exact match.