TV Size and Viewing Distance Calculator
Find a TV or monitor's width and height from its size in inches, and how far away to sit for the best view.
Width
121.8 cm (47.9 in)
- Height
- 68.5 cm (27 in)
- Good viewing distance
- 1.7 to 2.2 m
- Screen area
- 0.8339 m²
A 55-inch 16:9 screen is 121.8 cm wide and 68.5 cm tall. Sit about 1.7 to 2.2 m away.
How it's worked out
- Scale
55 ÷ √(16² + 9²)2.996 - Width × height
16 × 2.996 by 9 × 2.99647.9 × 27 in - Viewing distance
1.2 to 1.6 times the diagonal, for a 4K TV filling about 30° to 40° of your view1.7 to 2.2 m
- Measure the wall or stand space against the width, and allow a few centimetres for the frame.
The formulas
Width = diagonal × w ÷ √(w² + h²) · Height = diagonal × h ÷ √(w² + h²) · Viewing distance ≈ 1.2 to 1.6 × diagonal
Worked example
A 55-inch 16:9 screen: 55 ÷ √(16² + 9²) = 2.996, so it's 47.9 × 27.0 inches, or 121.8 × 68.5 cm. Sit about 1.7 to 2.2 m away.
Questions people ask
How wide is a 55-inch TV?
A 16:9 55-inch TV is about 121.8 cm wide and 68.5 cm tall, plus the frame.
How far should I sit from a 55-inch TV?
About 1.7 to 2.2 metres for a 4K TV.
Is the screen size measured diagonally?
Yes, from one corner of the picture to the opposite corner, not including the frame.
About this calculator
Formula and rules last checked 25 October 2026Written and tested by the CalculatorDex teamReport a problem