# Pixels Per Inch Calculator

Calculate PPI from screen resolution and diagonal size. Check retina quality at your viewing distance. Compare pixel density for monitors, phones, and tablets.

## What this calculates

How sharp is your screen? Enter the resolution and diagonal size to calculate the pixel density in PPI. The calculator also checks whether individual pixels are visible at your typical viewing distance, so you can tell if your display qualifies as retina quality.

## Inputs

- **Horizontal Resolution** (pixels) — min 1
- **Vertical Resolution** (pixels) — min 1
- **Screen Diagonal** (inches) — min 1, max 200
- **Viewing Distance (optional)** (inches) — min 4 — Distance from your eyes to the screen

## Outputs

- **Pixels Per Inch (PPI)**
- **Dot Pitch** — Physical distance between pixel centers
- **Total Pixels** — formatted as text — Resolution in megapixels
- **Retina Quality?** — formatted as text — Whether individual pixels are visible at your viewing distance

## Details

PPI (pixels per inch) measures how tightly packed the pixels are on a display. Higher PPI means sharper text and images. But whether you can actually see the difference depends on how far you sit from the screen.

PPI benchmarks for common devices:

  - Desktop monitors (27"): 82 PPI (1080p), 109 PPI (1440p), 163 PPI (4K)

  - Laptops (15.6"): 141 PPI (1080p), 188 PPI (1440p), 282 PPI (4K)

  - Tablets (10.9"): 264 PPI (iPad Air)

  - Phones (6.1"): 460 PPI (iPhone 15 Pro)

The "retina" concept was popularized by Apple to describe displays where individual pixels cannot be distinguished at a normal viewing distance. For a desktop monitor at 24 inches away, about 143 PPI qualifies. For a phone held 12 inches away, you need about 286 PPI.

## Frequently Asked Questions

**Q: What PPI is considered retina quality?**

A: It depends on viewing distance. For a phone held at 12 inches, about 286 PPI qualifies. For a desktop monitor at 24 inches, about 143 PPI is enough. For a TV viewed from 8 feet away, even 40 PPI looks smooth. The formula is roughly 3438 / viewing distance in inches.

**Q: Is higher PPI always better?**

A: Not necessarily. Once PPI exceeds the retina threshold for your viewing distance, the human eye cannot tell the difference. A 500 PPI phone screen does not look sharper than a 400 PPI phone screen at normal holding distance. Higher PPI does increase GPU workload and power consumption.

**Q: What is dot pitch?**

A: Dot pitch is the physical distance between the centers of adjacent pixels, measured in millimeters. It is the inverse of PPI. A lower dot pitch means smaller, more tightly packed pixels and a sharper image. For example, 100 PPI equals a dot pitch of 0.254 mm.

**Q: How do I find my screen's diagonal size?**

A: Measure from one corner of the visible screen area to the opposite corner. Do not include the bezel (frame). Alternatively, look up your monitor model number online and check the specifications. Common sizes are 24, 27, and 32 inches for desktop monitors.

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Source: https://vastcalc.com/calculators/everyday/pixels-per-inch
Category: Everyday Life
Last updated: 2026-04-08