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Last updated: 3 October 2026
Fence panel calculator
Work out panels, posts and concrete for a new fence. UK units: metres, centimetres and litres. Results update as you type.
How to use this calculator
Measure the total length of the fence line. Enter the width of your panels.
This calculator assumes one straight run. Add an extra post for each corner, gate or change of direction.
How it's calculated
Panels = fence length ÷ panel width, rounded up. Posts = panels + 1 for a straight run. Concrete is posts × bags per post.
Worked example
A 20 m run with 1.83 m panels: 20 ÷ 1.83 = 10.93, rounded up to 11 fence panels and 12 posts.
Common questions
How many bags of concrete per post?
It depends on the post size, hole size and product. Check the instructions on the bag, which usually state how many bags a typical post needs.
Do I need planning permission or approval?
Rules on fence height and boundaries vary by area. Check with your local council or authority before building.
What if my fence has a gate?
Reduce the length by the gate width and add gate posts separately.