Turn a width × height (e.g. 1920×1080) into its simplified aspect ratio (16:9), or expand a ratio into resolutions.
Design • ratio
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Aspect ratio is the proportional relationship between width and height — 1920×1080 simplifies to 16:9, the standard for HD/4K video and most monitors. Knowing the ratio matters for video editing, photography, web design and fitting content to screens without stretching or black bars.
Enter a resolution to get its simplified ratio, or enter a ratio to get matching resolutions. Instant and browser-based.
An aspect ratio is width divided by height, reduced to its simplest whole-number form by dividing both by their greatest common divisor. It matters because scaling an image to a different ratio either distorts it or crops it — there is no third option. Common ratios carry history: 16:9 became the television standard as a geometric compromise between 4:3 broadcast and 2.35:1 cinema, while 3:2 comes from 35 mm film and persists in most cameras. Knowing the ratio lets you solve for a missing dimension, which is the everyday use when resizing for a fixed width or height.
Ratio = Width : Height, divided by GCD(Width, Height)New height = New width × (Height ÷ Width)New width = New height × (Width ÷ Height)where:
Assumptions: Assumes square pixels, true of essentially all modern displays. Some legacy video formats used non-square pixels, where storage dimensions and display aspect ratio differ.
Reduce a familiar resolution, then resize it to a fixed width without distortion.
Result1920 × 1080 = 16:9 — resizes to 1280 × 720
The 2560 × 1600 case is worth noting: 8:5 is the same as 16:10, a ratio common on laptops and frequently mistaken for 16:9. Placing 16:9 video on a 16:10 display leaves letterbox bars, which is a ratio mismatch rather than a fault.