Screen Width Calculator
Find the width and height of your screen using its diagonal size and aspect ratio.
How the Screen Width Calculator Works
Screen sizes are usually listed by diagonal measurement, such as a 55-inch TV. However, the actual width and height of the screen depend on its aspect ratio. This calculator uses the Pythagorean theorem to determine the exact width and height from the diagonal.
Formula
Width = Diagonal × (Aspect Ratio Width ÷ √(Aspect Ratio Width² + Aspect Ratio Height²))
Height = Diagonal × (Aspect Ratio Height ÷ √(Aspect Ratio Width² + Aspect Ratio Height²))
Example Calculation
For a 100-inch diagonal screen with a 16:9 aspect ratio:
Width ≈ 100 × (16 ÷ √(16² + 9²)) = 87.2 inches
Height ≈ 100 × (9 ÷ √(16² + 9²)) = 49.0 inches
Common Aspect Ratios
- 16:9: Standard for HDTVs, projectors, and modern monitors.
- 4:3: Traditional TVs and some projectors.
- 21:9: Ultra-wide monitors and cinematic screens.
- 3:2: Many laptops and tablets.
- 1:1: Square screens or specialty displays.
Why Screen Dimensions Matter
Knowing the width and height of your screen is essential for:
- Projector placement and throw distance calculations
- Choosing the right TV stand or wall mount
- Determining viewing distance for optimal picture quality
- Planning room layouts for home theaters
FAQs
Why does a 55-inch TV not seem 55 inches wide?
Because the measurement is diagonal. The width will be less, depending on the aspect ratio.
Can I use this calculator for projector screens?
Yes. It works for TVs, projectors, computer monitors, and any display with a known aspect ratio.
What if my aspect ratio is not listed?
You can calculate manually if you know the ratio values, or request a custom option for advanced use.
Conclusion
Our Screen Width Calculator takes the guesswork out of screen sizing. With just your diagonal measurement and aspect ratio, you’ll know the exact width and height of your display, making it easy to plan for projectors, TVs, and monitors in any space.