Aspect Ratio Calculator
Enter any screen diagonal, width, or height to instantly calculate all dimensions. Choose from preset aspect ratios or enter a custom one.
Screen Size Calculator
Select an aspect ratio and enter any dimension to calculate the rest.
1. Choose Aspect Ratio
2. Enter a Dimension
Results
Diagonal
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Width
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Height
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Area
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Visual Preview
Common Screen Sizes
| Size | Width | Height | Type |
|---|---|---|---|
| 24" | 20.9" | 11.8" | Monitor |
| 27" | 23.5" | 13.2" | Monitor |
| 32" | 27.9" | 15.7" | Monitor |
| 43" | 37.5" | 21.1" | TV |
| 55" | 47.9" | 27.0" | TV |
| 65" | 56.7" | 31.9" | TV |
| 75" | 65.4" | 36.8" | TV |
Understanding Aspect Ratios
What is Aspect Ratio?
Aspect ratio is the proportional relationship between a screen's width and height, expressed as two numbers separated by a colon (e.g., 16:9). It describes the shape of the screen, not its size. A 16:9 screen is always wider than it is tall by the same proportion, whether it's a 5-inch phone or a 75-inch TV.
The Formula
Given diagonal d and aspect ratio w:h:
- Width = d × w ÷ √(w² + h²)
- Height = d × h ÷ √(w² + h²)
- Area = Width × Height
Common Aspect Ratios
| Ratio | Decimal | Common Uses |
|---|---|---|
| 16:9 | 1.78 | Most monitors, TVs, laptops, YouTube |
| 16:10 | 1.60 | MacBook displays, some business monitors |
| 4:3 | 1.33 | iPad, older monitors, projectors |
| 21:9 | 2.33 | Ultrawide monitors, cinema |
| 32:9 | 3.56 | Super ultrawide monitors (Samsung Odyssey) |
| 3:2 | 1.50 | Surface laptops, photography |
| 1:1 | 1.00 | Instagram posts, square displays |
Frequently Asked Questions
How to calculate screen aspect ratio?
To calculate a screen aspect ratio, divide the horizontal resolution (or physical width) by the vertical resolution (or height) and reduce both numbers by their greatest common divisor (GCD). For instance, a 1920×1080 display reduces to 16:9 (1920/120 : 1080/120 = 16:9). You can also divide width by height directly to express it as a decimal ratio (e.g., 1.78:1).
Is my screen 16:9 or 16:10?
Check your current screen resolution in your operating system display settings. Divide the horizontal pixel count by the vertical pixel count: a decimal value of ~1.78 (such as 1920×1080, 2560×1440, or 3840×2160) indicates 16:9, while a value of exactly 1.6 (such as 1920×1200, 2560×1600, or MacBook displays) indicates 16:10.
How do I calculate a ratio?
To calculate a ratio between two numbers A and B, divide both numbers by their greatest common factor to express them as simplified whole numbers (e.g., 24 and 18 share a GCD of 6, giving 4:3). Alternatively, divide A by B to get a normalized ratio relative to 1 (e.g., 24 ÷ 18 = 1.33:1).