CattleScale ruler sheet

Print this page on A4 at 100% scale (not "fit to page"), then keep it flat: a clipboard or a sheet of cardboard behind it works.

1. Check the bar at the bottom measures 100 mm with a tape. If it does not, reprint at 100%.
2. Clip the sheet to the rail or hold it flat against the animal's shoulder, facing the camera squarely.
3. Keep it in the same plane as the animal's side, at about shoulder height, and in every photo you can.

The square is 16 cm on each side. The app reads it to work out how many centimetres each pixel covers, so height, length and girth are measured rather than assumed from the breed.

This bar is 100 mm long when printed correctly.