How to use this calculator
Start by entering the total linear footage of your fence line. Choose your fence height and style, then specify how many gates you need and your preferred post spacing. The calculator instantly shows the number of posts, rails, pickets, and bags of concrete required.
Use the "Customize prices" option to enter your local lumber prices for a more accurate cost estimate. The default prices reflect typical big-box store pricing for pressure-treated pine.
Fence styles explained
Privacy fences use boards placed edge-to-edge with no gaps. They block sightlines completely and are the most popular choice for backyard boundaries. They require the most lumber but offer maximum screening.
Semi-privacy fences leave small gaps (about 1-2 inches) between boards. They allow some airflow and light through while still providing good screening. This style uses roughly 25% fewer boards than a full privacy fence.
Picket fencesspace boards evenly apart, typically with gaps equal to the board width. They're ideal for front yards and decorative boundaries where full privacy isn't needed. They use about half the boards of a privacy fence.
Fence materials comparison
| Material | Lifespan | Maintenance | Cost range |
|---|---|---|---|
| Pressure-treated pine | 15 to 20 years | Stain every 2 to 3 years | $12 to $25/ft |
| Cedar | 20 to 30 years | Seal every 3 to 5 years | $18 to $35/ft |
| Vinyl | 25 to 30 years | Occasional washing | $20 to $40/ft |
| Aluminum/steel | 30+ years | Minimal | $25 to $50/ft |
Permits and regulations
Most cities and counties require a building permit for fences, especially those over 6 feet tall. Contact your local building department before starting, permit fees typically range from $20 to $100 and the process can take a few days to a few weeks.
If you live in an HOA community, check your covenants for restrictions on fence height, style, material, and color. Many HOAs require architectural review approval before construction. Setback requirements usually keep fences 2 to 6 inches inside your property line, and front yard fences are often limited to 3 to 4 feet in height.
Frequently asked questions
How many fence posts do I need?
Divide your total fence length by your post spacing (typically 8 feet), then add 1 for the end post. Add 2 extra posts for each gate. For example, a 100-foot fence with 8-foot spacing and one gate needs 16 posts.
How deep should fence post holes be?
Post holes should be about one-third the total post length plus 4 inches for gravel drainage. For a 6-foot fence, use 8-foot posts buried about 2.5 feet deep. The hole should be 3 times the post width in diameter.
How much concrete do I need per fence post?
Plan on 1 bag of 60-lb concrete for 4-foot fence posts and 2 bags for 6-foot or 8-foot fence posts. Fast-setting concrete is ideal for fence posts since you don't need to mix it, just pour it dry into the hole and add water.
Do I need a permit to build a fence?
Most municipalities require permits for fences, especially those over 6 feet tall. Check with your local building department and HOA (if applicable) before starting. Fines for unpermitted fences can be significant, and you may be required to remove the fence.