Find your monitor or phone's physical screen size in inches using pixel density. No measuring tape required.
This is an estimate based on pixel density. Actual size may vary by ±10% depending on your display's true DPI.
Screen size is measured diagonally from corner to corner in inches. A 15.6-inch laptop screen means the diagonal distance is 15.6 inches. Common sizes include: smartphones (5-7"), tablets (8-13"), laptops (13-17"), monitors (24-32"), and TVs (40-85"+).
The calculation uses your screen resolution divided by the display's pixel density (DPI) to estimate the physical dimensions in inches, then applies the Pythagorean theorem for the diagonal.
We use your screen resolution and device pixel ratio (DPR) to estimate physical dimensions. Physical pixels equal CSS pixels times DPR. At 96 DPI, each inch has 96 CSS pixels. The diagonal is calculated using the Pythagorean theorem. This is an estimate as actual DPI varies slightly by manufacturer.
Smartphones: 5.5-6.8 inches. Tablets: 8-13 inches. Laptops: 13-17 inches. Desktop monitors: 24-32 inches for most users. Screen size alone does not determine sharpness because PPI (pixels per inch) matters equally.