Understanding Fence Material Calculations
The most important rule in fence building is the $\mathbf{N+1\ Rule}$ for posts: a fence with 'N' sections requires $\mathbf{N+1}$ posts (a starting post and an end post). This calculator automatically accounts for the extra post needed to complete the run.
Key Fence Planning Factors
Gate Posts and Corner Posts
The calculator provides a straight-line estimate. If you have **corners** or **gates**, you must treat those sections as separate runs or ensure those posts are heavy-duty. Corner posts and gate posts are under maximum stress and should often be larger or set deeper than line posts.
Post Depth and Concrete
A general rule is to set the post $\mathbf{1/3\ of\ its\ length}$ in the ground. For instance, an $8\text{-foot}$ post should be set $\approx 2.5\text{-feet}$ deep. The amount of concrete needed depends heavily on the diameter and depth of your hole. Always consult product packaging for exact bags per hole diameter.
Calculating Pickets and Rails (for stick-built fences)
Picket/Rail Estimation
If you are building a fence from scratch (not using pre-built panels), you'll need to calculate:
- **Rails:** Multiply the total fence length by the number of horizontal rails (e.g., $100\text{ ft} \times 3\text{ rails} = 300\text{ linear feet of rail material}$).
- **Pickets:** For a standard $6\text{-inch}$ picket with a $\mathbf{1/4\text{-inch}}$ gap, you need approximately $\mathbf{2\text{ pickets}}$ per $\mathbf{1\text{ linear foot}}$ of fence.