# Display Resolution Calculator

Free display resolution calculator. Calculate PPI (pixels per inch), aspect ratio, megapixels, and physical dimensions for any screen resolution and size.

## What this calculates

Calculate pixel density (PPI), aspect ratio, total megapixels, and physical screen dimensions for any display. Enter the resolution and screen size to see detailed display specifications.

## Inputs

- **Width (pixels)** — min 1
- **Height (pixels)** — min 1
- **Screen Diagonal (inches)** — min 0.1

## Outputs

- **Pixels Per Inch (PPI)** — Pixel density of the display.
- **Total Pixels** — formatted as text — Total number of pixels (width x height).
- **Aspect Ratio** — formatted as text — The simplified aspect ratio.
- **Resolution Name** — formatted as text — Common name for this resolution, if applicable.
- **Megapixels** — Total pixels expressed in megapixels.
- **Screen Dimensions** — formatted as text — Physical width and height of the display in inches.

## Details

Understanding display resolution and pixel density helps you choose monitors, TVs, and mobile devices.

Key Metrics

- PPI (Pixels Per Inch): Higher PPI means sharper text and images. Most people cannot distinguish individual pixels above 300 PPI at normal viewing distance.

- Aspect Ratio: The proportional relationship between width and height. Common ratios: 16:9 (widescreen), 16:10 (productivity), 21:9 (ultrawide), 4:3 (classic).

Common Resolutions

- 720p (1280x720): HD, budget TVs

- 1080p (1920x1080): Full HD, most common

- 1440p (2560x1440): QHD, gaming monitors

- 4K (3840x2160): UHD, premium displays

- 8K (7680x4320): Ultra premium

PPI Examples

- 24" 1080p monitor: ~92 PPI

- 27" 4K monitor: ~163 PPI

- iPhone 15: ~460 PPI

- MacBook Pro 14": ~254 PPI

## Frequently Asked Questions

**Q: How is PPI calculated?**

A: PPI = diagonal resolution in pixels / diagonal size in inches. Diagonal pixels = sqrt(width² + height²). For a 24" 1920x1080 display: diagonal = sqrt(1920² + 1080²) = 2203 pixels, PPI = 2203 / 24 = 91.8 PPI.

**Q: What PPI is considered 'Retina' quality?**

A: Apple defines 'Retina' as a pixel density where individual pixels are indistinguishable at normal viewing distance. This is roughly 300+ PPI for phones (held at ~10-12 inches), 220+ PPI for tablets, and 100+ PPI for laptops (viewed at arm's length). The threshold depends on viewing distance.

**Q: Is 4K always 3840x2160?**

A: Consumer '4K' (UHD) is 3840x2160. Cinema 4K (DCI) is 4096x2160, which is slightly wider. The '4K' name refers to approximately 4,000 horizontal pixels. Some ultrawide '4K' monitors use 5120x2160. Always check the exact resolution.

**Q: What aspect ratio is best?**

A: 16:9 is the standard for video content and gaming. 16:10 provides extra vertical space for productivity (documents, code). 21:9 ultrawide is great for immersive gaming and multitasking. 4:3 is rare now but was the standard before widescreen adoption.

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Source: https://vastcalc.com/calculators/technology/resolution
Category: Technology
Last updated: 2026-04-21