# Screen PPI Calculator

> Calculate pixel density, pixel pitch, aspect ratio and the viewing distance where pixels blend for any monitor, TV or phone screen.

Page: https://freecalculator.tech/tools/screen-ppi-calculator
Last reviewed: 2026-11-03

## Formula

PPI = √(width² + height²) ÷ diagonal. Pixel pitch = 25.4 ÷ PPI mm. Distance where one pixel spans 1 arcminute = 1 ÷ (PPI × tan(1/60°)).

- 1 arcminute (1/60 of a degree) is the conventional resolution of 20/20 vision.
- PPI = √(width² + height²) ÷ diagonal. Pixel pitch = 25.4 ÷ PPI mm. Distance where one pixel spans 1 arcminute = 1 ÷ (PPI × tan(1/60°)).
- Inputs used: Horizontal pixels, Vertical pixels, Screen diagonal, Viewing distance (optional).

## Inputs

- Horizontal pixels
- Vertical pixels
- Screen diagonal
- Viewing distance (optional)

## Worked example: 27-inch 2560 × 1440

√(2560² + 1440²) ÷ 27 ≈ 108.79 PPI; pixels blend at about 31.6 inches.
1. Diagonal pixels = √(6,553,600 + 2,073,600) ≈ 2,937.2.
2. PPI = 2,937.2 ÷ 27 ≈ 108.79.
3. Distance = 1 ÷ (108.79 × 0.00029089) ≈ 31.6 in.

## Common questions

### Is higher PPI always better?

Only until pixels are too small to see at your distance. Beyond that, extra resolution is hard to notice.

### What is the 1-arcminute rule?

Typical 20/20 vision resolves detail about 1/60 of a degree wide, so smaller pixels blend together.

### Does it work in centimetres?

Enter the diagonal and distance in inches; the blending distance is also shown in centimetres.

### How do I use the Screen PPI Calculator?

Enter the required values for Horizontal pixels, Vertical pixels, Screen diagonal, Viewing distance (optional). The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.

### What formula does the Screen PPI Calculator use?

PPI = √(width² + height²) ÷ diagonal. Pixel pitch = 25.4 ÷ PPI mm. Distance where one pixel spans 1 arcminute = 1 ÷ (PPI × tan(1/60°)). The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.

### Can the Screen PPI Calculator be used for exact decisions?

Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.

## Limitations and assumptions

- Assumes square pixels.
- Visual acuity varies between people and with contrast and content.
- Does not account for scaling or subpixel layout.
- Geometric estimates. The 1-arcminute limit describes typical 20/20 acuity; individual eyesight differs.
- The result depends on the values you enter for this screen ppi calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.

## Sources

- Wolfram MathWorld — https://mathworld.wolfram.com/ArcMinute.html

## Cite this page

- APA: Free Calculator. (2026, November 3). Screen PPI Calculator. https://freecalculator.tech/tools/screen-ppi-calculator
- MLA: "Screen PPI Calculator." Free Calculator, 3 Nov. 2026, https://freecalculator.tech/tools/screen-ppi-calculator.
- Link: Screen PPI Calculator — Free Calculator, https://freecalculator.tech/tools/screen-ppi-calculator