Aspect ratio describes the relationship between frame width and height. It is not the same as resolution. A 1920 × 1080 image and a 1280 × 720 image are both 16:9, but have different pixel counts.
Start with where the video will appear
Landscape 16:9 fits many desktop players and presentations. Vertical 9:16 is common for full-screen short-form viewing. Square 1:1 and portrait 4:5 may be used for social feeds. Platform recommendations and safe areas can change, so check the destination's current upload guidance before exporting.
Plan the crop while you still have room
Changing from landscape to vertical removes a large amount of horizontal picture unless you have enough room to reframe the subject. Keep faces, captions, and important objects inside a safe region. A calculator can suggest canvas dimensions but cannot decide which part of a shot should stay visible.
What Framewell's calculator returns
The Frame Size Calculator finds the largest even-pixel frame that preserves your chosen ratio inside a maximum width and height. It may leave unused space in that box and does not read or resize your source. Use a video editor or encoder to crop or scale the actual video.
Ratio versus display shape
Most modern web video uses square pixels, but legacy media can contain pixel-aspect or rotation metadata that affects display. If a file appears stretched or rotated, inspect its media metadata and playback path rather than assuming the width-to-height ratio alone explains it.