Inputs
Recommended post size: 125mm × 125mm
Typical post length (incl. below ground): 2.40m
Results
Enter your fence details then click Calculate.
UKUK Building Regulations
References & Sources
Standards Cited
- BS 1722 — Fences — Specification for wooden fences
Defines standard fence panel sizes (typically 1.83m/6ft wide), post dimensions, and construction requirements - FCA Guidelines — Fencing Contractors Association — Installation Guidelines
Industry guidance on post depth, concrete requirements, and gravel board usage
Formulas Used
- Panels Required:
panels = ceil(fenceLength / panelWidth)
Source: BS 1722 - Posts Required:
posts = panels + 1 (both ends free) or panels (one end against wall)
Source: BS 1722 — Posts at each panel junction, plus end posts where fence is free-standing - Post Depth:
depth = max(fenceHeight x 0.33, 600mm)
Source: FCA installation guidelines — Minimum 600mm depth; one-third of fence height for taller fences - Concrete per Post:
1 x 25kg bag per post (standard); 2 bags for fences >1.5m or concrete posts
Source: FCA installation guidelines - Total Fence Height:
totalHeight = fenceHeight + gravelBoardHeight
Source: BS 1722
Key Assumptions
- Standard fence panel width is 1.83m (6 ft) — BS 1722
- Post depth is one-third of fence height with a minimum of 600mm — FCA installation guidelines
- 1 bag (25 kg) of postcrete per standard post hole; 2 bags for taller/heavier fences — FCA installation guidelines
- Gravel board height typically 150-300mm — BS 1722