Every fence layout ends with a number that does not divide. A 300-foot run of 6-foot panels is perfect arithmetic that real lots ruin: slopes stretch runs, gates eat width, and the final bay arrives at 3.7 feet. How a builder handles that bay separates layout craft from panel-stacking.
Option one: cut the last panel
Cut a panel to the remainder and accept one narrower bay. It is honest, fast, and invisible at the far corner where it belongs — always plan the cut bay at the least-visible end of the run, and never in the middle of a sightline or beside a gate.
Option two: redistribute the spacing
Divide the run by the panel count plus one: 310 ÷ 51 = 6.08-foot bays. Every bay grows by an inch; picket rhythm stays uniform; the difference is invisible. This is the professional default on long runs — the only cost is slightly wider gate-adjacent spacing to remember when hanging hardware.
Option three: rack or step
Slopes convert the remainder problem into a geometry problem. Racked panels pivot on the rails to follow grade (the continuous, no-gaps look — needs rackable panels or site-built sections). Stepped fences hold panels level and step down in drops — the terraced look that leaves triangular gaps requiring a wider post or trim boards. Slope over 15–20% usually forces one of these explicitly.
The layout procedure
- Stretch mason string on the actual line (including slope effects — the fence follows the ground, not the plat).
- Mark gate locations first — gates anchor the layout, not the other way around.
- Run the panel calculator numbers: exact bays, remainder, and the redistribute-or-cut decision.
- Stake every post location before any digging — walking the stake line at eye level reveals problems strings hide.
The odd bay is not an error to hide; it is a decision to make in daylight, on paper, before the concrete truck is booked. That is the entire difference between fence projects that end clean and ones that end with one panel cut badly at the gate.