Fence Calculator
Enter your fence run and post spacing to get posts, rails, pickets, and the concrete to set them.
Posts needed
16 posts
Rails
39
Pickets
192
Concrete bags
16
Rail sections
13
At the defaults above (100 ft run, 8 ft post spacing, 1 gate) that's 16 posts, 39 rails, 192 pickets, and 16 bags of concrete.
How it's calculated
Post count is your fence run divided by the spacing, plus one for the starting post -- the same "runs of spacing, plus one" logic used to count fence posts across most published consumer fence calculators. Rails run between each pair of posts; pickets are counted from the total run in inches divided by each picket's width plus its gap. Gates add their own posts and are excluded from the picket run, since a gate is its own pre-built unit.
Keep going
- Fencing and decking are commonly built in the same project and share the same post-and-joist logic; the deck calculator covers the deck surface itself. Deck Calculator
- Fencing a whole property line rather than a yard? The acreage calculator helps translate a lot's acreage into a rough perimeter to fence. Acreage Calculator
Frequently Asked Questions
Should I space posts every 6 ft or every 8 ft?
8 ft spacing uses fewer posts and is common for taller privacy fences with heavier rail sections; 6 ft spacing is more common for shorter picket or split-rail fences, or where local wind load or fence height calls for closer support.
How many bags of concrete per post?
One 50 lb bag of fast-setting concrete mix per hole is the standard manufacturer guidance for a typical residential line post -- larger or gate posts commonly take 2. For the concrete mix volume itself (bags vs. cubic yards for a bigger pour), see StoneCalc's concrete calculator.
Do gates need extra posts?
Yes -- a gate needs its own posts on both sides to carry the hinges and latch hardware, which is why this calculator adds 2 posts per gate on top of the line-post count. A real layout can sometimes share a post between a gate and an adjacent run; this is a simplification most consumer fence calculators use.
How do I size the gap between pickets?
A common privacy-fence gap is under an inch (often 1/4"-1/2"); a picket fence with visibility through it commonly runs a gap close to or wider than the picket itself. Check your specific style's typical spacing before finalizing.
How many rails does my fence need?
3 rails is a common default for a standard privacy or picket fence; taller fences (6 ft+) or ones expecting more wind load sometimes use more. Check your specific fence style and local code before finalizing.