Fence Calculator
Plan a wood privacy, picket, vinyl panel or chain link fence in one place. Enter the length, height, corners and gates. You get posts, boards or panels, rails, chain link fabric, hardware, post-hole size and bags of concrete.
Everything is calculated in your browser. Nothing you type is sent or stored.
Posts = (fence length ÷ post spacing) + 1, plus one for every corner and gate. A 150 ft, 6 ft tall wood privacy fence with 8 ft spacing, 2 corners and one 4 ft gate needs 23 posts, 57 rails, about 335 1×6 boards and 60 bags of 80 lb concrete.
How to use this fence calculator
- Pick the fence type. Wood privacy (boards butted tight), picket (boards with gaps), pre-made vinyl or wood panels, or chain link.
- Enter the total length of every run added together, the height, the number of corners and the number of gates.
- Set post spacing for wood and chain link, or panel width for panel fences.
- Read the order list: posts with the length to buy, boards or panels, rails, concrete, and hardware for chain link.
How many fence posts do I need?
| Straight fence length | Posts at 6 ft | Posts at 8 ft | Chain link at 10 ft |
|---|---|---|---|
| 50 ft | 10 | 8 | 6 |
| 100 ft | 18 | 14 | 11 |
| 150 ft | 26 | 20 | 16 |
| 200 ft | 35 | 26 | 21 |
| 300 ft | 51 | 39 | 31 |
Spacing resets at every corner and gate, which is why each one adds a post. Wood privacy and picket fences use 6–8 ft spacing. Shorter spacing makes a stiffer fence in high-wind areas. Chain link line posts should never be more than 10 ft apart.
Post hole size and concrete per post
Make the hole about three times the post width and dig it to half the above-ground height (never less than 2 ft, and below your frost line). Put 4–6 in of gravel in the bottom for drainage.
| Fence height | Post | Hole | Concrete per post | 80 lb bags |
|---|---|---|---|---|
| 4 ft | 4×4 | 10–12 in × 2 ft | ~1.0 ft³ | 2 |
| 6 ft | 4×4 | 10–12 in × 3 ft | ~1.5 ft³ | 3 |
| 6 ft (gate post) | 6×6 | 16 in × 3 ft | ~3.6 ft³ | 6 |
| 8 ft | 6×6 | 16–18 in × 4 ft | ~5.1 ft³ | 9 |
These figures subtract the volume of the post itself. For an exact count per hole, including fast-setting mixes, use the fence post concrete calculator.
How many boards, pickets and rails?
| Style | Board (actual) | Gap | Per 8 ft section | Per 100 ft |
|---|---|---|---|---|
| Privacy, 1×6 | 5.5 in | 0 | 18 | 219 |
| Privacy, 1×4 | 3.5 in | 0 | 28 | 343 |
| Picket, 1×4 | 3.5 in | 2.5 in | 16 | 200 |
| Shadowbox, 1×6 | 5.5 in, both sides | — | ~27 | ~330 |
Rails: two per section up to 4 ft high, three for 5–6 ft fences and four for 8 ft fences. Use pressure-treated 2×4s rated for ground contact near the soil.
Chain link fence materials
- Terminal postsHeavier posts (often 2⅜ in) at each end, every corner and both sides of each gate.
- Line postsLighter posts (often 1⅞ in) between terminals, no more than 10 ft apart.
- Fabric and top railFabric is sold in 50 ft rolls at the fence height. Top rail comes in roughly 10½ ft swedged sticks that slip together.
- HardwareOne tension bar per fabric end, tension bands about every foot of height on terminals, and ties every 12–24 in on line posts and rail.
For a full hardware list, use the chain link fence calculator.
Wood, vinyl or chain link?
| Fence | Typical lifespan | Maintenance | Best for |
|---|---|---|---|
| Pressure-treated wood | 15–20 years | Stain or seal every 2–3 years | Privacy on a budget, easy DIY |
| Cedar | 15–30 years | Optional sealing | Natural look, less warping |
| Vinyl | 20–30+ years | Wash occasionally | Low maintenance, clean look |
| Galvanized chain link | 15–20+ years | Very little | Security, pets, large areas |
Worked example
- 150 ft, 6 ft privacy, 1 gate, 2 corners
- 146 ft of boards (gate removed)
- Sections at 8 ft
- ⌈146 ÷ 8⌉ = 19
- Posts
- 19 + 1 + 2 + 1 = 23
- Rails (3 per section)
- 57
- 1×6 boards (+5%)
- 146 × 12 ÷ 5.5 × 1.05 = 335
- Concrete (1.55 ft³ per hole)
- 60 × 80 lb bags
All 6 fencing calculators
Detailed calculators for each part of a fence project.
Frequently asked questions
How many fence posts do I need?
Divide length by spacing, round up, add one, then add one per corner and gate. A straight 100 ft fence at 8 ft spacing needs 14 posts.
How far apart should fence posts be?
6–8 ft for wood privacy and picket fences, the panel width for vinyl (6 or 8 ft), and at most 10 ft for chain link line posts.
How many bags of concrete per fence post?
About 2–3 bags of 80 lb concrete for a 4×4 on a 6 ft fence in a 10–12 in hole 3 ft deep. An 8 ft fence on 6×6 posts needs about 8–9 bags per post.
How deep should fence posts be?
Half the above-ground height, never less than 2 ft, which means 3 ft for a 6 ft fence. In cold climates, go below the frost line.
How many fence boards do I need?
Length in inches ÷ (board width + gap). With 1×6 boards butted tight, an 8 ft section needs about 18. Add 5% for splits and culls.
How many rails does a fence need?
Two per section up to 4 ft, three for 5–6 ft fences and four for 8 ft fences.
Fence post guides
What this calculator assumes
- Each gate opening is 4 ft and is subtracted from boards and rails. Gate posts are counted separately.
- 4×4 posts (3.5 in actual) up to 6 ft high, 6×6 posts (5.5 in) for 8 ft fences. Hole diameter is 3× post width, depth is half the fence height (min 2 ft).
- Concrete is 80 lb bags at 0.60 ft³ each, with the post volume subtracted. Boards include 5% spare.
- Check local code, HOA rules and utility locations (call 811 in the US) before digging.