Home › How To Measure Fence Line

How To Measure Fence Line

Before you measure: know where the line is

Fences built on the wrong side of a property line cause expensive disputes. Many people assume a fence should sit exactly on the line; in practice many owners keep their fence slightly inside their own property. Start with your property survey or plot plan, and look for survey pins (metal markers) at corners. If you cannot find reliable markers or there is any doubt, a land surveyor can mark the boundary. Read fence permits and property lines.

Tools you need

• Wooden or plastic stakes and a mallet
• Mason's string or bright line
• A 100 ft (30 m) tape or a measuring wheel
• Marking paint or flags
• A notepad or phone sketch of the yard
• A line level or laser for slopes

Step-by-step

1. Sketch your yard and the fence line, noting the house, trees, driveways and gates.
2. Set a stake at each end and each corner.
3. Run string between stakes, pulling it tight and straight.
4. Measure each straight segment along the string; write it on the sketch.
5. Mark gate locations and widths (walk gates commonly 3–4 ft, drive gates wider).
6. Add segments for the total fence length; list the number of corners, ends and gates.
7. Note slopes: measure the rise from one end to the other.
8. Re-measure each segment once to catch errors.

Measuring wheels versus tapes

Measuring wheels are fast on lawns but can read long over bumps and tall grass. Tapes along a tight string are more accurate. On long rural runs, a wheel or GPS walk is practical; on a city lot, use a tape. For any figure you will order materials from, double-check with a tape.

Online map tools

Online map "fence calculators by address" let you trace a line on aerial imagery. They are handy for a first estimate, especially on farms. But imagery can be offset by several feet, property lines shown are approximate, trees hide corners, and nothing tells you about slopes or obstacles. Treat map results as a ballpark for the acreage fence calculator or a first budget, then measure on the ground.

Worked example

Figures below are illustrative examples (2026-10-29), not quotes or guarantees.

Assumptions: a rectangular backyard with the house wall forming the fourth side. Measured segments: left side 72 ft, back 58 ft, right side 72 ft, and a 4 ft gate on the left side near the house. Total line = 202 ft, including the gate opening. Fence length to build = 198 ft plus one 4 ft gate. Corners: 2 at the back. Ends: 2 against the house. Gate posts: 2. Enter 198 ft in the fence calculator with 2 corners and 1 gate.

Handling curves and odd shapes

For gentle curves, measure along the curve with a tape following the string staked at several points. Each straight span between posts should be close to your planned spacing. For irregular lots, break the line into straight segments and add them.

Slopes and grade changes

Measure horizontal distance for spacing and the rise for planning stepped or racked sections. A line level on a taut string from the high stake to a tall stake at the low end lets you measure how far the ground drops. Steep slopes may change the number of posts and the need for longer posts.

Obstacles

Trees, rocks, utility boxes and easements can force the line to jog. Do not attach fence boards to trees; growing trunks damage fences and fasteners damage trees. Leave space around utility pedestals for access. Note downspout outlets and drainage swales: a fence across a drainage path can create a dam.

Recording your measurements

Keep your sketch with dimensions, photos of survey markers and a note of locate tickets. These help with permits, quotes and resolving disputes later.

Measuring for different fence types

Wood stick-built: total length and gate count are enough; the calculator handles spacing. Pre-built panels or vinyl: you need each straight run's exact length so you can plan how many full panels fit and where a cut panel goes; place cut panels at the least visible end. Chain link: total length for fabric and top rail plus the number of ends, corners and gates for terminal posts. Farm wire: total length and the location of every brace assembly; dips and rises need extra posts.

Checking square corners

For a 90° corner, use the 3-4-5 method: measure 3 ft along one line and 4 ft along the other; the diagonal between those points should be exactly 5 ft. For more accuracy, use 6-8-10 or 9-12-15. Square corners matter most when fencing against a house or a square patio.

Double-check with a second person

Measuring alone with a long tape invites errors from sagging tape, misread feet and inches, or a hook slipping off a stake. Have one person hold the end on the stake while the other reads, and record each segment immediately.

Recording your measurements

Draw a simple sketch, label each segment with its length, mark every corner, end and gate with its width, and note slopes or obstacles. Photograph it with your phone so it is with you at the store or when talking with an installer.

FAQ

Do I measure to the outside or centre of posts?

Measure the line itself; the calculator handles post count from spacing.

Should I include gate widths in total length?

Measure the total line, then subtract gate openings for fence length, and count gates separately.

How accurate do I need to be?

Within a foot or two is fine for budgeting; exact for ordering panels.

What spacing?

See fence post spacing.

Try the calculator · Back to FAQ & guides