Quick answer: Enter your total fence length, height, post spacing and fence style, and this calculator estimates the posts, pickets or boards, rails, gates and concrete you need, including a waste allowance. The defaults are 30 m long, 1.8 m high, 2.4 m post spacing, spaced picket style and 5% waste. It is free, with no signup. See also: How Many Moving Boxes Do I Need? and Epoxy Resin Calculator.
Plan a fence without guessing. Enter your fence length, height and style, and this calculator estimates the posts, pickets or boards, rails, gates and concrete you need, including a waste allowance.
Fence Material Calculator
m for length, height, spacing and gate width; mm for board width, gap and hole diameter.
Advanced concrete estimate
Bag yield varies by product. Check the manufacturer's packaging before buying.
Your fence estimate
| Item | Quantity |
|---|
How this fence material calculator works
Sections = ceiling(total fence length ÷ post spacing). Posts = sections + 2 + (2 × number of gates). Infill length = total fence length − total gate width. Approx. fence area = total fence length × fence height. For spaced pickets, picket pitch = board width + gap; for privacy boards and pre-built panels the gap is treated as 0. Pickets or boards = ceiling(ceiling(infill ÷ pitch) × (1 + waste ÷ 100)). Rails = ceiling((sections × rails per section) × (1 + waste ÷ 100)). Concrete: hole volume = π × (hole diameter ÷ 2)² × hole depth, and bags are rounded to the nearest whole bag (posts × hole volume ÷ yield per bag).
Honest estimate caveat
This is a planning estimate. Actual quantities depend on your exact boundary, post positions, gate hardware and the real dimensions of the boards or panels you buy. Measure the actual boundary and check product dimensions before ordering.
Practical fence planning tips
- Measure the actual boundary, including slopes and corners.
- Check the real dimensions of the boards, panels and posts you plan to buy.
- Keep the waste allowance realistic for cuts and breakages.
- Plan gates first, because gate posts and hardware change the post count.
- Check the concrete yield on the bag you actually buy.
- Allow for terrain, roots and uneven ground.
How this calculator works
This calculator works from the length of fence you need, not from a guess. It first divides the run into sections, then works out the posts, infill, rails and concrete from those sections. The gate opening is taken out of the infill length, but gate posts are still counted, because a gate needs posts on both sides.
Sections = total fence length ÷ post spacing, rounded up. Posts = sections + 2 + (2 × number of gates). Infill length = total fence length − total gate width. For a spaced picket, the picket pitch is board width + gap; for a privacy fence the gap is treated as 0. Pickets = infill length ÷ picket pitch, rounded up, then increased by the waste allowance and rounded up again. Rails = sections × rails per section, increased by the waste allowance and rounded up. Concrete is based on the hole volume, π × (hole diameter ÷ 2)² × hole depth, with bags rounded to the nearest whole bag.
Worked example: a 30 m spaced-picket fence
Use the default inputs: 30 m total length, 1.8 m height, 2.4 m post spacing, spaced-picket style, 100 mm boards, 50 mm gap, 3 rails per section, 1 gate of 1 m, and 5% waste.
- Sections: 30 ÷ 2.4 = 12.5, rounded up to 13 sections.
- Posts: 13 + 2 + (2 × 1) = 17 posts, including the gate posts.
- Infill length: 30 − 1 = 29 m. The approximate fence area is 30 × 1.8 = 54 m².
- Pickets: pitch = 100 + 50 = 150 mm. 29,000 ÷ 150 = 193.33, rounded up to 194 pickets, then × 1.05 = 203.7, rounded up to 204 pickets.
- Rails: 13 × 3 = 39, then × 1.05 = 40.95, rounded up to 41 rails.
- The tool also gives 42 concrete bags as its estimate for these defaults.
Check the result in the same order: if the sections or post count look wrong, the length, spacing or gate count is usually the cause, because every other quantity follows from those values.
Quick reference: what changes the count most
Change Effect on the estimate Wider post spacing Fewer sections and fewer posts, but longer rails and infill runs per section Adding a gate Adds 2 posts and removes the gate width from the infill length Wider picket gap Fewer pickets for the same infill length More rails per section More rails in direct proportion to the number of sections Higher waste allowance Raises the picket and rail counts to cover cuts and damaged pieces
Measure the actual boundary, including corners and slopes, before ordering, and check the real board, panel and bag sizes you plan to buy.
Fence calculator FAQ
How this calculator works
This calculator works from the length of fence you need, not from a guess. It first divides the run into sections, then works out the posts, infill, rails and concrete from those sections. The gate opening is taken out of the infill length, but gate posts are still counted, because a gate needs posts on both sides.
Sections = total fence length ÷ post spacing, rounded up. Posts = sections + 2 + (2 × number of gates). Infill length = total fence length − total gate width. For a spaced picket, the picket pitch is board width + gap; for a privacy fence the gap is treated as 0. Pickets = infill length ÷ picket pitch, rounded up, then increased by the waste allowance and rounded up again. Rails = sections × rails per section, increased by the waste allowance and rounded up. Concrete is based on the hole volume, π × (hole diameter ÷ 2)² × hole depth, with bags rounded to the nearest whole bag.
Worked example: a 30 m spaced-picket fence
Use the default inputs: 30 m total length, 1.8 m height, 2.4 m post spacing, spaced-picket style, 100 mm boards, 50 mm gap, 3 rails per section, 1 gate of 1 m, and 5% waste.
- Sections: 30 ÷ 2.4 = 12.5, rounded up to 13 sections.
- Posts: 13 + 2 + (2 × 1) = 17 posts, including the gate posts.
- Infill length: 30 − 1 = 29 m. The approximate fence area is 30 × 1.8 = 54 m².
- Pickets: pitch = 100 + 50 = 150 mm. 29,000 ÷ 150 = 193.33, rounded up to 194 pickets, then × 1.05 = 203.7, rounded up to 204 pickets.
- Rails: 13 × 3 = 39, then × 1.05 = 40.95, rounded up to 41 rails.
- The tool also gives 42 concrete bags as its estimate for these defaults.
Check the result in the same order: if the sections or post count look wrong, the length, spacing or gate count is usually the cause, because every other quantity follows from those values.
Quick reference: what changes the count most
| Change | Effect on the estimate |
|---|---|
| Wider post spacing | Fewer sections and fewer posts, but longer rails and infill runs per section |
| Adding a gate | Adds 2 posts and removes the gate width from the infill length |
| Wider picket gap | Fewer pickets for the same infill length |
| More rails per section | More rails in direct proportion to the number of sections |
| Higher waste allowance | Raises the picket and rail counts to cover cuts and damaged pieces |
Measure the actual boundary, including corners and slopes, before ordering, and check the real board, panel and bag sizes you plan to buy.
How many posts do I need? Count one post per section, plus end and gate posts. This calculator uses posts = sections + 2 + (2 × gates).
How much concrete do I need? It depends on hole diameter, hole depth and bag yield. The advanced section estimates bags from those three values.
Should I add waste? Yes. A 5% allowance covers cuts and damaged pieces; use more for irregular boundaries.
Does it work in metric and imperial? Yes. Switch units at the top of the calculator and the inputs convert between metres/feet and millimetres/inches.