Pole Barn Post Spacing Calculator
Estimate bay spacing, post count, and footing concrete for a cleaner pole barn layout
📋Quick Presets
Post Spacing Results
Enter your barn dimensions and load settings to size the wall run.
📊Full Breakdown
🖨Reference Tables
| Snow | 4x6 | 6x6 | 8x8 |
|---|---|---|---|
| 20 psf | 8 ft | 12 ft | 14 ft |
| 30 psf | 7 ft | 10 ft | 12 ft |
| 50 psf | 6 ft | 8 ft | 10 ft |
| 70 psf | 5 ft | 7 ft | 8 ft |
| Truss | Spacing factor | Effect | Typical use |
|---|---|---|---|
| 4 ft | 1.08 | Wider bays | Heavy roof |
| 5 ft | 1.00 | Base value | Standard build |
| 6 ft | 0.92 | Slight trim | Mixed loads |
| 8 ft | 0.85 | Tighter bays | Open spans |
| Post | Hole dia | Depth | Concrete |
|---|---|---|---|
| 4x6 | 16 in | 4 ft | 0.46 yd3 |
| 6x6 | 18 in | 4.5 ft | 0.65 yd3 |
| 8x8 | 24 in | 5 ft | 1.09 yd3 |
| 10x10 | 30 in | 5.5 ft | 1.79 yd3 |
| Footprint | Long wall | Short wall | Perimeter |
|---|---|---|---|
| 24x32 | 4 posts | 4 posts | 12 posts |
| 30x40 | 5 posts | 4 posts | 14 posts |
| 36x48 | 6 posts | 5 posts | 18 posts |
| 40x60 | 6 posts | 5 posts | 18 posts |
🛠Material and Spec Grid
Subtract door width before you lock the bay count, because wide openings often force extra posts and smaller gaps near the edge.
This calculator gives a practical layout estimate. Final post spacing should still match local snow load, soil, and framing rules.
Building a Pole Barn
Before building a pole barn, you must determine the numbers of posts the pole barn will need and the distance between those posts. The distance between the posts, also known as post spacing, is a critical component of pole barn building. If the distance between the posts is too wide for the buildings specification, the wall of the barn may sag.
Additionally, if the distance between the posts is too narrow, the cost of building the pole barn may increase for the posts need. Several factor will impact the number of posts a pole barn will need. Some of those factor include the snow load that the barn will take, the wind load the barn may experience, and the type of wall that will be built within the barn.
How Many Posts and How Far Apart for a Pole Barn
The snow load for a pole barn is the weight that the posts will take from the snow that accumulate on the roof of the barn. If the snow load for a barn is high, the distance between the posts must be shorter to accommodate the high snow load. Another factor that will play a role in determining the number of posts for a pole barn is the wind load.
The wind load is the force that the wind will apply to the side of the pole barn. If the wind load is very high for a barn, the distance between the posts will have to be shorter to allow for tight spacing for the posts to resist the force of the wind. The type of wall that will be constructed for the pole barn will also play a role in determining how many posts the pole barn will need.
Most pole barns will have at least one long wall for the barn, and the long wall will have door. When adding a door to a long wall, you must subtract the width of the door from the length of the wall. This is because the door will create an opening in the wall, removing part of the wall from the barn.
Additionally, there are various types of wall for a pole barn. For example, the side walls of a pole barn are not the same than the open lean-to walls for the barn. Open lean-to walls dont have bracing for the barn like the other wall of a pole barn.
Therefore, lean-to wall require a shorter distance between the poles to ensure that the lean-to barn does not fall over. Another factor that plays a role in determining the distance between the posts for a pole barn is the size of the posts. If the posts that are used for the barn are larger, such as 8×8 foot posts, then the distance between the posts can be wider than if smaller post are used.
For example, if 4×6 foot posts are used for the barn, the distance between the posts has to be shorter because a 4×6 foot post can take less weight than an 8×8 foot post. Thus, the larger the posts for a pole barn, the more wider the distance between the posts. However, posts with a large diameter will cost more money to build the pole barn.
The overhang for a pole barn can also affect the distance between the posts. The overhang is the portion of the barns roof that project beyond the wall of the barn. This overhang for the barn can act as a cantilever.
A cantilever can place a torque on the posts for the barn. Therefore, if the overhang for a pole barn is more than two feet wide, the distance between the posts should be shorter to the pole barn. Additionally, the depth of the posts should be considered.
The posts for a pole barn should be deep set into the ground to ensure that the barn can resist the uplift of the posts caused by the wind. Another calculation that must be made when building a pole barn is the number of posts the barn will need, the distance between those posts, and the amount of concrete that will be needed for the footing of the barn. The diameter of the hole and the depth of the hole for the footings will determine the amount of concrete needed for the footings for the poles.
If the pole barn is expected to have a high snow load or if the wind load on the barn will be high, the diameter of the holes will have to be wider. The type of soil in which the pole barn will be built can also affect the amount of concrete needed for the footings. If the soil in which the pole barn will be built is sand or clay soil, then it will not be as stable as soil with sand or clay particle.
In this case, wider footings will be needed to build the pole barn to ensure its stability. Finally, local building code will also play a role in determining the posts that must be used for the pole barn. Local building codes may require certain distances between the posts.
Additionally, the codes may state the depth to which the posts must be embedded into the ground to allow for the barn to be stable. In some local building codes, if the snow load on the barn is going to be very high, an engineer may be required to approve the distance between the poles for that barn. For these reason, the individual who plans to build a pole barn should of consult with the local building department to determine what local codes will be required to build the pole barn.
