How to measure for a fence

Before you bid, walk the property: the property line, each fence run, the gates and the old fence. A worked example and a free calculator are waiting at the end.

Fence calculator

What to bring

A tape measure or a measuring wheel
The property survey, for the property line
Stakes and string to lay out the runs
Your phone to record and photograph each run in a MesuPro survey

Before digging: call 811 a few business days ahead in the US, or Info-Excavation in Quebec, so buried utilities are marked. Also check your city's fence bylaw (height, setback) and whether a permit is needed.

Step by step

Find the property line
The property survey shows it. If the fence follows it, agree with the neighbor before laying out, and photograph the markers.
Split the fence into runs
Each straight line between two corners or ends is a run. Record its length, style, height and the terrain: flat, sloped or stepped.
Count the posts from your spacing
The spacing is the length of your panels or rails, center to center. Sections = length / spacing, rounded up, and posts = sections + 1. Two runs that meet share the corner post.
Record the gates separately
Type, width, height and which way they open, with their posts. For a pool enclosure under the 2024 ISPSC, the barrier is at least 48 in, stops a 4 in sphere, and its gate opens outward and closes and latches on its own.
Calculate the concrete for the holes
The hole diameter, the post width, the concrete depth and the yield printed on your bag give the concrete per hole and the bags to buy, rounded up to the bag.

The calculation

For each run: sections = length / spacing, rounded up, and posts = sections + 1 (each run has its two ends). Rails = sections x rails per section. Pickets = length / (picket width + gap), rounded up. Concrete per hole = (pi x diameter² / 4 - post width²) x concrete depth: a square post in a round hole. Bags = posts x concrete per hole / concrete per bag, rounded up on the total. No spacing, hole size or bag yield comes filled in: they are yours and the bag's.

Worked example

On the fictitious backyard of the demo "Fence - Backyard with pool, Columbus OH", the 80 ft left side and the 100 ft back in wood privacy, with posts 8 ft apart, make 180 ft: 25 posts, 23 sections, 69 rails at 3 per section and 394 pickets 5.5 in wide. Holes 10 in across for 4 in posts, with 24 in of concrete, take 0.87 cu ft each, so 58 bags of 0.375 cu ft. The aluminum pool side is calculated on its own, with its own spacing.

Try it with your numbers