The basics
What aspect ratio means
Aspect ratio describes the proportional relationship between a frame’s width and height, independent of its total pixel count.
Resolution planning
Aspect Ratio & Resolution Calculator
Simplify a video resolution into its exact aspect ratio, or calculate a matching width or height for a target ratio.
Calculator
Choose what you need to find
Pixel dimensions and custom ratios use positive whole numbers. Calculated dimensions are rounded to the nearest whole pixel when needed.
Find a ratio
Reduce the resolution
Width and height are divided by their greatest common divisor. For example, 1920 × 1080 reduces exactly to 16:9.
Match a resolution
Calculate the other side
Apply the target ratio to a known width or height. If the result is fractional, it is rounded to the nearest whole pixel and may differ slightly from the target ratio.
Related tools
Put your chosen resolution to work
Check whether a delivery resolution fits YouTube guidance, then estimate the file size your bitrate may create.