Fence panel calculator: estimate panels and posts before asking for a quote
Use this planning tool for a straightforward fence run. It subtracts a gate opening and estimates how many full-width panel bays you may need. It is not a structural design or an order list: a contractor must confirm exact spans, corners, posts and supports.
1.83 m is a common nominal panel width in the UK; confirm the actual supplier dimensions and post centres before buying.
The fence length excluding the gate is approximately 14.1 m.
A gate usually needs dedicated support posts; corners, returns and changes of direction change the total.
How to measure a garden fence correctly
- Mark each straight run separately. A corner or step is usually a change of direction, not one uninterrupted straight fence.
- Measure the gap where each gate will sit. Don't include that opening in the panel run, but do allow for proper gate posts and clearances.
- Record slopes and ground levels. Stepped panels and raked panels can use different bay layouts.
- Check exact panel and post-centre sizes. The advertised size may differ from the installed clear width.
- Ask the installer to confirm foundations. Soil, height, exposure, underground services and the chosen system all matter.
Worked example: 15 metres with one 900 mm gate
Subtract a 0.9 m gate opening from 15 m to leave 14.1 m of panelled fence. At a nominal 1.83 m bay width, 14.1 ÷ 1.83 is about 7.7, so plan for 8 panel bays, including any adjusted end bay. This does not mean all eight bays will be full-size, and a gate must be supported independently according to its design.
Why the estimate can differ from a contractor's materials list
| Site condition | What to discuss |
|---|---|
| A sloping boundary | Stepped or raked panels, varying post lengths |
| Corner or return | Extra corner posts and post orientation |
| Existing concrete posts | Reuse only if sound, correctly spaced and appropriate |
| Gate in the middle | Gate posts and hinges may need independent support |
| Exposed coastal garden | Wind resistance and suitable corrosion-resistant fixings |
| Buried pipes or cables | Safe digging and a suitable installation method |
Frequently asked questions
How many posts do I need for 10 panels?
For one continuous straight run with no gate, a simple starting estimate is 11 posts, one more than the number of bays. Corners, gates and other changes may require different supports.
Does this calculate the total price of a fence?
No. Labour, timber grade, removal, groundwork, fixings, gates, access and post dimensions vary. For meaningful comparisons, ask several businesses to price the same written specification.
Do I need planning permission?
In England, fence-height rules often depend on whether the fence is beside a vehicular highway, and heritage or local restrictions may apply. Read the Planning Portal guidance and check your local planning authority before work starts.
Next step: prepare a useful quote request
Keep your measurements and sketch handy. Use our free comparison worksheet or send a fencing enquiry to see whether we can introduce you to an independent contractor. UK Fencing Quotes is a lead-referral service, not a fencing installer; a quote or response is not guaranteed.
Sources and further reading: HM Land Registry on boundaries · Planning Portal on fences.