Current and target ratio
Run the test to see a visual synchronized with the current result.
Screen Aspect Ratio Calculator
Enter a screen width and height to calculate the current aspect ratio, or compare dimensions against a target ratio.
Settings
Enter a valid value.
Enter a valid value.
Enter a valid value.
Enter a valid value.
Enter a valid value.
Current conditions
Enter dimensions to calculate.
Simplified ratio—Enter dimensions to calculate.
- Simplified ratio
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- Decimal ratio
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- Relative ratio difference
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The result is calculated from the current width, height, and unit inputs; scaling, cropping, and pixel shape can also affect the displayed ratio.
Ratio visual
Learn more
Use and interpret
Enter width and height in the chosen unit. Use Simplify to show the current ratio, or choose a solve mode to calculate the missing dimension from the target a:b ratio.
Method and validation
The calculator reduces W:H by the greatest common divisor. Solve-height uses H = W × b/a; solve-width uses W = H × a/b. Relative difference is |(W/H)/(a/b) − 1| × 100%.
Width and height must be positive and within the field limits. The target ratio must contain two positive numbers separated by a colon; the unit changes labels, not the ratio.
Scope and limitations
This is a geometric calculation from the values you enter. It does not measure the panel or video signal; cropping, stretching, non-square pixels, and scaling can change visible content.
What aspect ratio is 1920×1080?
1920×1080 simplifies to 16:9.
How do I calculate height from a 16:9 width?
Multiply the width by 9 and divide by 16.
Why can the visible ratio differ from the resolution?
Cropping, stretching, black bars, non-square pixels, or scaling can change the visible result.
Privacy and implementation
This tool runs in the browser. It does not upload input, call a remote API, or write to local storage.
The page uses standalone HTML, CSS, and JavaScript without a third-party runtime library.