Measure the useful length
Do not use the outside width of the shed or the full worktop length if part of it holds equipment. Measure only where a person can actually sit with clear knee space. If a door swings across one end, or the hatch frame sits inside the run, use the end-clearance slider to take it out.
Read the result as a prompt
Stool widths, arms and the way people sit all differ. Adjust the per-person figure, then mark those positions on the real counter with tape. Check how people enter, leave and pass behind the seats. The counter height guide explains how to get the height and overhang right for your stools.
Test the whole route
The result says nothing about the door swing, the server's working space or a step behind the stools. Set the layout out at full size before cutting timber, and read accessible garden bars if anyone using it needs level access or a lower counter.