: Most builders recommend burying one-third of the total post length in the ground. For a standard 6-foot fence, the post should be at least 2 feet deep.
For more precise calculations, you can use tools like the Omni Fence Post Depth Calculator . How Deep And Wide Should Fence Posts Holes Be? 22084mp4
If you are instead asking about the technical specifications for a "deep post" (as in a structural fence post): : Most builders recommend burying one-third of the
: In colder climates, posts must be set below the frost line —often 36 to 48 inches deep—to prevent "frost heaving," where the ground pushes the post out as it freezes and thaws. 22084mp4