Screen viewing distance and angle
Find the viewing angle or seating distance for a monitor, TV or projector screen, using its diagonal and aspect ratio. Drag the graph handles to change inputs and explore the result.
Your inputs
The editable example is illustrative. Enter your own dimensions, operating data, prices, and fees. Results update as you edit.
Calculations run in your browser. Inputs are not saved or sent to analytics.
How it works
- Screen width = × ÷ √(² + ²)
- Horizontal viewing angle = 2 × atan(Screen width ÷ (2 × )) × 180 / π
- = Screen width ÷ (2 × tan( × π / 360))
- Worked example: 65″, 16:9, 2.5 m → 32.111°
Input and formula key
Your result
Complete the inputs to see your result.
Assumptions and limitations
For a flat rectangular screen viewed straight on from its center; distance is perpendicular to the screen. Angles describe the field of view, not the panel’s off-axis rating. OSHA’s preferred desk-monitor range is 20–40 inches, independent of screen size; adjust text size and posture. Sony’s TV references are 30° for everyday use and 40° for cinema. The projector reference adapts THX’s 36° commercial-cinema guidance for home planning. These are starting points; comfort, resolution and room layout vary. Curved screens and projector throw distance are not modeled.
Sources
- OpenStax — right triangle trigonometry Sources reviewed: 2026-10-22
- OSHA — preferred desktop monitor distance Sources reviewed: 2026-10-22
- Sony — 30° everyday and 40° cinema TV viewing Sources reviewed: 2026-10-22
- THX — 36° commercial cinema screen-placement reference Sources reviewed: 2026-10-22
