Split into straight runs
Measure from the first post centre to the last post centre. Exclude gate openings. Each run is split into equal bays that do not exceed the maximum centre spacing you enter.
08 / Boundaries & garden screens
Fence post and picket calculator
Estimate posts, pickets and rail pieces for straight open fence runs using post centres, face widths and gaps.
Know what goes into your estimate
A clearer fence material count
Measure between post centres, then plan the infill.
Check the clear bay
Subtract one post face width from the centre spacing to estimate clear space. Pickets round up per bay using (clear space + gap) ÷ (picket width + gap). Edge pickets may need cutting to fit.
Count shared posts once
Every open run starts with bays + 1 posts. Where two included runs share an end post, subtract one duplicate. Rail pieces equal bay count × the rail pieces per bay you enter.
How many fence posts and pickets?
Examples use at most 2.4 m between post centres, 100 mm post faces, 90 mm picket faces and 10 mm gaps. Bays are equal within each run. These inputs are quantity examples, not structural spacing specifications. Fixed panels and gates are outside this model.
| Open run length | Bays | Posts | Pickets with 10% extra |
|---|---|---|---|
| 6 m | 3 | 4 | 66 |
| 12 m | 5 | 6 | 132 |
| 18 m | 8 | 9 | 194 |
| 24 m | 10 | 11 | 264 |
These are examples, not product specifications. Enter your own measurements and product details in the calculator above.
Common questions
What does the 12 m example produce?
At a maximum 2.4 m post-centre spacing, 12 m gives five bays and six posts. With 100 mm posts, each bay has 2.3 m clear space. At 90 mm picket faces and 10 mm gaps, each bay needs 24 pickets: 120 before allowance, or 132 with 10% extra. Two rail pieces per bay gives ten pieces.
Is this for prefabricated fence panels?
No. Fixed panels have their own exact dimensions and post systems. This tool divides open runs into equal bays for site-built picket infill; use your panel supplier’s setting-out instructions for panel fencing.
How do I handle gates and corners?
Exclude each gate opening and enter the adjoining fence as separate runs. Corners shared by two runs create one duplicate end-post count to subtract. Gate hardware and additional gate posts are not automatically added. Closed loops are outside this open-run model.
Can I buy stock rails from the rail-piece count?
The result counts pieces per bay, not stock lengths. The table shows clear bay widths, but rail joints and supports depend on the fence system. Prepare a cutting and support plan before ordering timber.
Where can I check product-specific fencing quantities?
Jacksons Fencing’s planning tools illustrate how actual fencing systems need their own posts and accessories. This independent picket model does not reproduce a manufacturer’s panel specification.