TVs, monitors and smartphones are quoted in inches worldwide – but what does "65 inches" actually mean for your living room? Will a 55-inch TV fit into a 120 cm wide TV alcove? And how far should you sit from the screen? The screen size converter doesn't just give you the diagonal in centimeters – it also helps you judge whether a device will work visually in your space. Electronics retailers list all display sizes in inches, and the metric measurement is almost never shown.
Step by Step: How to Use the Screen Size Calculator
- Enter the inch value: Type the inch size of the device you're looking at – e.g. 55 for a 55-inch TV.
- Read the conversion: The calculator shows the diagonal in centimeters: 55 inches = 139.7 cm.
- Derive width and height: For a 16:9 display: width = diagonal × 0.872, height = diagonal × 0.490. For 55 inches: width approx. 121.8 cm, height approx. 68.5 cm.
- Check your installation space: Measure your TV unit and compare with the calculated screen width (add roughly 2–5 cm for the bezel).
- Work out viewing distance: As a rule of thumb: distance = 2–3 × diagonal in cm. For 55 inches: 280–420 cm recommended.
Practical Examples
Example 1 – Buying a TV for the living room: Your TV sideboard is 150 cm wide; the TV should sit centrally with 15 cm clearance on each side. Maximum TV width: 120 cm. A 65-inch TV has a screen width of 65 × 2.54 × 0.872 = 143.9 cm – too wide! A 55-inch TV at 121.8 cm fits perfectly.
Example 2 – Gaming monitor for your desk: You're looking for a 27-inch monitor. 27 × 2.54 = 68.58 cm diagonal. Width in 16:9: approx. 59.8 cm, height: approx. 33.6 cm. On a 120 cm wide desk you can run two of these monitors side by side.
Example 3 – Comparing smartphone displays: iPhone 15 Pro (6.1 inches) vs. Samsung Galaxy S24 Ultra (6.8 inches): 6.1 × 2.54 = 15.5 cm vs. 6.8 × 2.54 = 17.3 cm diagonal. That 1.8 cm difference translates to roughly 25% more display area.
Screen Diagonal: Inches to Centimeters
Common screen sizes: 32" = 81.3 cm; 43" = 109.2 cm; 55" = 139.7 cm; 65" = 165.1 cm; 75" = 190.5 cm.
Frequently Asked Questions (FAQ)
- Why are screens measured in inches rather than centimeters?
- The inch measurement for screens originated in the US, where the first commercial TV sets were developed in the 1940s. The convention became a global standard – even in countries that use the metric system. Only a few markets briefly used centimeter measurements.
- Does the inch figure refer to the visible area or the bezel?
- The inch figure refers exclusively to the diagonal of the visible display area, not including the bezel. Two monitors with the same inch rating can differ in overall size if one has a narrower frame.
- What screen size is ideal for a given viewing distance?
- As a rule of thumb: viewing distance in cm divided by 2.5 to 3 gives the ideal diagonal in inches. At 250 cm: 250 ÷ 2.5 = 100 cm ÷ 2.54 = about 39 inches minimum, 55 inches optimal. With 4K resolution you can sit closer, since individual pixels are not visible.
