Screen Size Calculator
Calculate screen diagonal size from width and height, or find width/height from diagonal. Useful for comparing monitor and TV sizes.
How to Use This Calculator
- To find diagonal: Enter width and height in inches, and the calculator displays the diagonal size.
- To find width: Enter height and diagonal, and the calculator calculates the width.
- To find height: Enter width and diagonal, and the calculator calculates the height.
- Use this to compare screen sizes, plan display setups, or verify manufacturer specifications.
Screen Size Formula
Screen dimensions are related by the Pythagorean theorem:
Width = √(Diagonal² - Height²)
Height = √(Diagonal² - Width²)
Example: A 23.5" wide × 13.2" tall screen: Diagonal = √(23.5² + 13.2²) = √(552.25 + 174.24) = √726.49 = 26.95" (approximately 27").
Full Description
Screen size is typically specified by diagonal measurement, but understanding the actual width and height dimensions is important for planning workspace layouts, comparing displays, and ensuring screens fit in designated spaces. This calculator helps you convert between diagonal size and actual dimensions, making it easier to compare different screens and plan your setup.
Diagonal measurement is the standard because it provides a single number that represents overall screen size, regardless of aspect ratio. However, two screens with the same diagonal can have very different dimensions if they have different aspect ratios. A 27" 16:9 monitor is wider and shorter than a 27" 21:9 ultrawide monitor, even though both have 27" diagonals.
Use this calculator to understand the actual dimensions of screens you\'re considering, plan desk space requirements, compare different aspect ratios, and verify manufacturer specifications. Whether you\'re shopping for a new monitor, planning a multi-monitor setup, or comparing TV sizes, this tool helps you make informed decisions based on actual dimensions rather than just diagonal size.
Frequently Asked Questions
How is screen diagonal measured?
Screen diagonal is measured from corner to opposite corner of the visible screen area (not including bezels). It's the standard way manufacturers specify screen size. A 27" monitor means the diagonal is 27 inches.
How do I find my screen's diagonal if I only know width and height?
Use the Pythagorean theorem: Diagonal = √(Width² + Height²). Enter width and height into this calculator, and it calculates the diagonal automatically.
Can I use this for TVs and monitors?
Yes! This calculator works for any rectangular screen—computer monitors, TVs, tablets, smartphones, or any display. Just enter the dimensions in inches.
Why is diagonal size important?
Diagonal size is the standard specification used by manufacturers and retailers. It helps you compare screen sizes across different brands and models. However, actual viewing area depends on aspect ratio—a 27" 16:9 monitor has different dimensions than a 27" 21:9 monitor.