Inner instead of outer
Measure the finished packed item, not the usable space inside it.
A calculator can reject zero or missing fields. It cannot know that the tape missed a protector, the wrong edge was measured or two different boxes were placed in one quantity row.

A calculator can reject zero or missing fields. It cannot know that the tape missed a protector, the wrong edge was measured or two different boxes were placed in one quantity row.
Measure the finished packed item, not the usable space inside it.
Use the furthest fixed protected point.
Keep the span straight and square to the measured faces.
Do not hide different sizes behind one quantity.
Label the result as a bounding-cuboid estimate.
CBM does not confirm fit, handling or acceptance.

A protrusion outside the nominal carton wall changes the maximum span. Measure to the protected outer point rather than the original wall.

A short note or photograph helps another person understand which edges were used. Keep private documents unreadable when sharing an image.

Measure the maximum bounding length, width and height as a planning estimate. The chosen provider must still confirm handling and acceptance.

Stretch wrap, corner protectors and a top cover can extend the boundary. Measure the finished packed unit.