The Screen PPI & Display Resolution Calculator computes pixel density (pixels per inch), physical screen dimensions, and dot pitch from diagonal display size and native resolution.

### Display Geometry & Pixel Density Formulas - Diagonal Resolution in Pixels: Computed using the Pythagorean theorem: $$d_{px} = \sqrt{W^2 + H^2}$$ - Pixel Density (PPI): Evaluates pixels packed along each linear inch: $$\text{PPI} = \frac{d_{px}}{\text{Diagonal Inches}}$$ - Dot Pitch: Measures center-to-center distance between adjacent physical pixels in millimeters: $$\text{Dot Pitch (mm)} = \frac{25.4\text{ mm/inch}}{\text{PPI}}$$ - Physical Panel Dimensions: Evaluated via trigonometric resolution aspect angle ($\theta = \arctan(H / W)$): $$\text{Physical Width (in)} = \text{Diagonal Inches} \times \cos(\theta)$$ $$\text{Physical Height (in)} = \text{Diagonal Inches} \times \sin(\theta)$$ - Total Megapixels: Evaluates overall panel pixel capacity: $$\text{Megapixels} = \frac{W \times H}{1{,}000{,}000}$$

### Worked Numeric Example Consider a 27-inch 4K UHD desktop monitor: - Native Resolution: $3840 \times 2160$ pixels - Diagonal Screen Size: $27.0$ inches - Calculated Display Specifications: - Diagonal Pixels: $\sqrt{3840^2 + 2160^2} = \sqrt{19{,}411{,}200} \approx 4406.4\text{ px}$ - Pixel Density: $4406.4 / 27.0 = 163.2\text{ PPI}$ - Dot Pitch: $25.4 / 163.2 = 0.1556\text{ mm}$ - Physical Width: $27.0 \times \cos(\arctan(2160/3840)) = 23.5\text{ inches}$ ($59.8\text{ cm}$) - Physical Height: $27.0 \times \sin(\arctan(2160/3840)) = 13.2\text{ inches}$ ($33.6\text{ cm}$) - Total Resolution: $8.29\text{ Megapixels}$

### In-Browser Processing Note All display measurements, pixel density calculations, and trigonometric formulas evaluate locally on your device with zero server logging.