Solve backwards
How long a fence will my posts set out?
- 10 postsThe example worked below
- Fence CalculatorEvery figure is its own
You have
How much fence posts?
Worked by the Fence Calculator at the settings below.
The settings it uses
- Post Spacing
- 8 ft (standard)
- Fence Height
- 5-7 ft
What it will do
Enough for 72 ft of fence.
One fence. Enough for 72 ft of fence.
Or several. Less than one fence of the size the Fence Calculator opens on (98 ft of fence).
Check it forwards
- Fence Length
- 72 ft
- It asks for
- 10 posts
- You have
- 10 posts
The Fence Calculator asks for 10 posts at that size, and 11 posts one step larger.
If you had more, or less
Around your amount
Each worked by the Fence Calculator at the same settings.
Half
5 posts
32 ft of fence
Yours
10 posts
72 ft of fence
Half as much again
15 posts
112 ft of fence
Double
20 posts
152 ft of fence
Common amounts
What each amount of fence posts covers
The sizes it is usually sold in, each worked by the Fence Calculator at the settings above.
| You have | It covers | As one fence | Average fences |
|---|---|---|---|
| 5 posts | — | 32 ft of fence | under 1 |
| 10 posts | — | 72 ft of fence | under 1 |
| 20 posts | — | 152 ft of fence | 1 |
| 40 posts | — | 312 ft of fence | 2 |
Eight feet between posts
Eight feet, about 2.4 m, is standard post spacing for most residential wood fences, and the calculator opens there; six feet suits taller fences, windy sites or heavier panels. Ten posts at 8 foot centres set out nine bays — 72 feet of fence — and at 6 foot centres only 54.
Corners and gates take their own posts
The answer is one straight run. Every corner, end and gate needs its own post — a gate usually two stout ones — and a fence that turns uses more posts than a straight one of the same length. Take those out of what you have before reading the length, and set gate posts deeper and in more concrete than line posts.
The last bay is a whole bay
A part-bay at the end is rounded up to a whole section, so the posts assume every bay runs the full spacing. Resetting the spacing on site to share a short bay across the run is usually neater. The concrete or gravel to set each post, and the post length below ground, are outside this count.
How the answer is worked
Nothing here is a second formula. The Fence Calculator runs forwards — a size in, a quantity out — and this page grows its own starting fence in proportion until the quantity it asks for is what you have. Where it rounds up to whole containers, the answer is the largest size before the next one would be needed.
Where the calculator adds an allowance for cuts or breakage when you order, the same allowance comes off here, because it is the same calculator: a stack you already own finishes less than its face value. Where it adds none, neither does this page — the settings beside the answer say which.
Fence Calculator
runs it forwardsEstimate the posts and rails needed for a wood fence run.
Work out what to buy insteadSolve backwards
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Solve backwards
Start from what is already in the yard
Paint, sheets, rolls, bags and pieces, each read the other way by the calculator that orders it.
The calculator's own figures
Nothing is estimated twice: the page runs the same calculator you would order with.
The largest size that fits
Where a calculator rounds up to whole containers, the answer stops before the next one.
Both unit systems
Gallons and litres, square feet and square metres, side by side.
Frequently asked questions
- How much fence does 10 posts of fence posts cover?
- At the Fence Calculator's own settings: Enough for 72 ft of fence. Every figure follows the settings, which you can change in the calculator.
- How many fence posts do I need for 100 feet?
- At 8 foot spacing, 100 feet divides into 13 bays (12.5 rounded up), so 14 posts for a straight run. At 6 foot spacing, 17 bays and 18 posts. Add a post for every corner and gate side. In metric, 30 metres at 2.4 m spacing is 13 bays and 14 posts.
- How far apart should fence posts be?
- Commonly 6 to 8 feet (1.8 to 2.4 m) for wood fencing — 8 feet for most residential fences, 6 for taller fences, windy sites or heavier panels. Prefabricated panels set the spacing by their own width.
- How many rails does a wood fence need?
- Two per bay for fences under 5 feet (1.5 m), three for 5 to 7 feet, and four for 8 foot fences, according to the calculator's source. More rails resist sagging and wind; the rail count grows with the number of bays the posts set out.