Split the layout into straight runs
Measure between corners, ends, and gates instead of treating the entire perimeter as one uninterrupted line.
This makes terminal posts and panel fit easier to verify.
Apply maximum spacing correctly
Post spacing is normally a maximum bay dimension, so divide the run and round up the number of spaces before deriving posts.
Exact spacing can be adjusted so bays finish evenly.
Count gates and corners separately
Gate, corner, end, and brace assemblies may use posts that differ from ordinary line posts.
Add these from the selected fence system rather than assuming every post is interchangeable.
Check panel width against the run
Prefabricated panels impose their own module and can force shorter end bays or layout changes.
Use actual panel dimensions and manufacturer clearances.
Verify site constraints
Property lines, utilities, easements, slopes, wind exposure, pool barriers, and permits can change layout and construction.
A quantity calculator does not establish compliance or post depth.