Reframe · alpha · worked example
How to calculate a vertical crop from a wide video
Turning a wide clip into a vertical frame discards much of the source. Work out the available width, then inspect subject movement across the whole clip.
Updated October 10, 2026 · by thecreatingco
A small example to work through
Our 1920 × 1080 source is cropped to 9:16 using its full height. The ideal crop width is 607.5 pixels, usually rounded to a practical whole-pixel width.
| Item | Example | Notes |
|---|---|---|
| Source | 1920 × 1080 | 16:9 landscape |
| Target ratio | 9:16 | Width = 1080 × 9 / 16 |
| Crop width | About 608 px | About 31.7 percent of source width |
| Centered crop | About x=656 to x=1264 | Subjects outside this band are lost |
Download the editable text worksheet · Download the CSV worksheet
Use the blank observation and decision fields to record your own result. These downloads are planning worksheets; they do not load an app project or demonstrate a completed export.
Try it and inspect the result
- Open Reframe and choose the intended output shape. Begin with a centre crop and identify the subject at the first frame.
- Watch the full clip, noting where the subject reaches the edges. Adjust the crop around action rather than around one attractive still.
- Review a small exported result if available. Confirm the output dimensions and inspect caption placement at the actual phone display size.
When the result differs
- Subject disappears midway
- Track movement through the clip and revise the framing; first-frame success is insufficient.
- Text is clipped
- Place text for the new frame rather than retaining landscape positions.
- Need everything in frame
- Use a layout with borders or a different composition; a crop cannot retain all source width.
What this example establishes
These dimensions are calculated from an example source, not Reframe output. Automatic framing is not a guarantee, and pixel rounding may differ by encoder. Judge the full motion and the final export.
This page supplies a worked example and a review method. It does not report a newly completed end-to-end app test. For current availability and edition details, read the Reframe overview.