Fence Post Depth Calculator

ft

Calculate the required burial depth and total post length for a fence post.

Formula

Burial depth = fence height × 1/3 (minimum 2 ft)
  • Rule of thumb: bury 1/3 of post length plus 6 inches.
  • Minimum depth: 2 ft (24 inches).
  • In frost zones, posts should reach below frost line.

6 ft fence, average soil

Inputs
  • Fence Height Above Ground: 6 ft
  • Soil Type: average

Depth = 6 × 0.333 = 2 ft. Total post = 6 + 2 = 8 ft.

Frequently asked questions

How deep below frost line?
Posts should extend below the local frost line depth (check local codes) to prevent heaving.