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Gravel Board Calculator — Boards, Clips & Materials

Calculate how many gravel boards and clips you need for your fence. Choose between concrete and timber boards to match your fence panels.

Choose how to specify your fence size

Total length of fencing

Concrete posts require gravel board clips

Include wastage allowance

Adds 10% extra for breakages

10% recommended — concrete boards can crack in transit


How We Calculate This

Our gravel board calculator works out the number of boards needed based on either your total fence run length or the number of fence bays. Each bay requires one gravel board.

The formula

Gravel boards = Fence length ÷ Board length (rounded up)
Or simply: Gravel boards = Number of fence bays
Clips = Boards × 2 (for concrete posts only)

For example, a 10m fence with 1.83m boards: 10 ÷ 1.83 = 5.46, rounded up to 6 gravel boards. With concrete posts, you would need 12 gravel board clips (2 per board).

Material comparison

  • Concrete gravel boards: 1.83m × 150mm × 50mm, weight approximately 20-25kg each. Rot-proof and maintenance-free. Slot into concrete post grooves
  • Timber gravel boards: 1.83m × 150mm × 22mm, pressure-treated softwood. Lighter and easier to handle but will eventually need replacing

Installation tips

  • With concrete posts, slide the gravel board into the bottom slot before fitting panels
  • Ensure a small gap between the board and the ground for drainage
  • On sloping ground, cut timber boards to follow the gradient or stack boards
  • Always install gravel boards before fence panels for easiest fitting

Frequently Asked Questions

Last updated: February 2026

All calculations are estimates. Verify with your supplier.