How it is calculated
The width of the gates is subtracted from the fence length. The rest divided by the post spacing gives the number of bays; there is one more post than bays plus one per gate. Metal sheets are counted by effective width and pickets by width plus gap. Fences up to 1.8 m have two rails, taller ones three.
Bays = (length − gates) ÷ post spacing, rounded upPosts = bays + 1 + number of gatesSheets = (length − gates) ÷ effective sheet widthExample
A 30 m fence of welded mesh panels 1.53 m high, with 4 m of gates and 2.5 m panels, needs 11 panels, 14 posts 2.35 m long, 56 clips and 0.55 m³ of concrete for the posts.
Tips from practice
- Set posts below frost depth or at least a third of their length into the ground.
- Check local rules on fence height between neighbours before you build.
- On windy, open plots keep bays at 2.5 m or less.
Questions and answers
How far apart should fence posts be?
Usually 2.5–3 m for metal sheets and 2.5 m for mesh panels; timber panels are 1.83 m wide.
How much concrete per post?
A 25 cm hole 0.8 m deep takes about 0.04 m³, roughly two 25 kg bags of post mix.
How wide are mesh fence panels?
Standard width is 2.5 m, with heights from 1.03 to 2.03 m.
Found a mistake in a formula? Write to contact@planicalc.com