What is PPI and why does it matter?

PPI measures linear pixel density. A higher value reduces pixel angular size, while perceived sharpness also depends on distance, scaling, rendering and eyesight.

What does the reference distance mean?

It is the geometric point where one pixel subtends roughly one arcminute. It is a calculation convention, not a universal perception threshold.

Monitor PPI & Pixel Density Calculator

By MonitorSmith editorial team · EXVORN.TECH • Updated September 23, 2026 • Editorial process

A geometric calculator for pixel density (PPI), nominal dot pitch and the distance where one pixel subtends about one arcminute.

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Interface and local controls remain in Portuguese.

How to use

Enter horizontal and vertical display resolution or choose a preset.
Specify the visible screen diagonal in inches.
Compare PPI, dot pitch and the angular reference with your distance, eyesight and scaling preference.

When to use

Comparing pixel density and nominal pixel size before a purchase.
A geometric reference for considering visible pixel structure.
Supporting an operating-system interface scaling choice.

Limitations

Calculations use the entered resolution and diagonal, assuming square pixels and flat geometry. Nominal diagonals, curves, system scaling and subpixel geometry can differ from the model.

Frequently Asked Questions

What is PPI and why does it matter?: PPI measures linear pixel density. A higher value reduces pixel angular size, while perceived sharpness also depends on distance, scaling, rendering and eyesight.
What does the reference distance mean?: It is the geometric point where one pixel subtends roughly one arcminute. It is a calculation convention, not a universal perception threshold.

Technical Methodology & Display Science

Pixel density is derived from the Euclidean diagonal pixel count divided by physical diagonal in inches: PPI = sqrt(W² + H²) / D. Dot pitch is the exact metric reciprocal: 25.4 mm / PPI.

The angular reference uses one arcminute and the approximation Distance (cm) ≈ 8732 / PPI. Actual acuity, contrast, subpixel geometry and content can change perception.

Reproduce this example in the calculator: select 27" 1440p (2560 × 1440). The result is 108.79 PPI, a 0.2335 mm dot pitch and an 80 cm angular reference. Keep the 27" diagonal and switch to 3840 × 2160: the results become 163.18 PPI, 0.1557 mm and 54 cm. These values are calculated from the inputs, not measurements of two physical monitors.

Interface scaling is an operational preference influenced by distance, eyesight, display size, operating system and application; the tool does not prescribe a universal value.