Display Calculator
Viewing Distance
Calculate optimal viewing distances based on THX, SMPTE, and Visual Acuity standards.
Display Settings
inch
px
px
40
PPI
47.9″
Width
27.0″
Height
16:9
Ratio
Reference
Standards & Guidelines
TV – THX / SMPTE
THX recommends 40 deg FOV for immersive viewing. SMPTE EG-18-1994 recommends minimum 30 deg for professional environments.
Distance = Width / (2 x tan(FOV/2))
Source: THX Ltd., SMPTE EG-18-1994
Monitor – Ergonomics
Ergonomic guidelines recommend 20-30 inches (50-76cm) for desktop monitors. Arm’s length is a practical rule.
Optimal: 20-30″ (50-76cm)
Source: Mayo Clinic, AOA, ISO 9241, OSHA
Tablet & Phone
Tablets: 12-20 inches recommended. Smartphones: approximately 12 inches. Closer viewing increases eye strain.
Tablet: 12-20″ / Phone: ~12″
Source: American Optometric Association
Visual Acuity
Based on 20/20 vision (1 arcminute). Beyond this distance, you cannot perceive the full resolution.
Max Distance = 3438 / PPI (inches)
Source: Snellen Chart, Apple Retina Formula
Sources
- THX Ltd. – Viewing Distance Recommendations (thx.com)
- SMPTE EG-18-1994 – Screen Dimensions
- Mayo Clinic – Office Ergonomics Guide
- American Optometric Association – Digital Devices
- ISO 9241-306:2018 – Ergonomics of Human-System Interaction
- OSHA – Computer Workstation Guidelines