Aspect Ratio Calculator
Calculate the decimal aspect ratio of any rectangle so you can resize video, graphics, or architectural plans without distortion.
Check results against project requirements before finalizing dimensions.
Examples
- 1920 × 1080 video frame ⇒ 1.777778 ratio (16:9)
- 1080 × 1920 vertical story ⇒ 0.5625 ratio (9:16)
- 297 mm × 210 mm A4 sheet ⇒ 1.414214 ratio (√2:1)
FAQ
Can I calculate height from a desired ratio?
Yes. Divide the known width by the ratio output here to solve for height.
How do I simplify the ratio into whole numbers?
Multiply both width and height by a common factor and round to the nearest integer. Use 16:9, 4:3, 1:1, etc., as shorthand for common results.
What if the result is less than 1?
It means the layout is taller than it is wide (portrait orientation). You can invert the ratio if you prefer width expressed relative to height.
Does pixel aspect ratio affect this calculation?
This tool assumes square pixels. For anamorphic footage, adjust pixel aspect ratio first before entering frame dimensions.
Additional Information
- Divide width by height to obtain the decimal aspect ratio; multiply by 100 to express as a percentage of height.
- To convert back to a colon notation, scale both width and height by the same factor until they become whole numbers (for example 1.777... ⇒ 16:9).
- Maintaining a consistent ratio avoids stretching graphics in responsive layouts, video encoding, and print design.