How to check whether a metes and bounds description actually closes

Every metes-and-bounds legal description makes a promise: follow the bearings and distances from the point of beginning and you end up back where you started. The "closure check" — running the traverse and measuring how far the last point lands from the POB — is how you find out whether that promise is true before you draft, file, or insure around it.

What "closure" means

A boundary description is a list of courses: a bearing like N 45°12'30" E paired with a distance like 212.40 feet. Starting at the POB, each course produces a new point. If the description is geometrically consistent, the final course ends at the POB. The gap between where the traverse ends and where it began is the misclosure (or "error of closure").

Surveyors grade the misclosure with the precision ratio: traverse perimeter divided by misclosure. A 2,000 ft parcel closing to 0.5 ft is roughly 1:4,000. Older deeds legitimately close looser than modern work — context matters — but a gross misclosure usually means a transcription error, not sloppy surveying.

Checking it by hand

1. List the calls. Write down every course in order — bearing quadrant first (NE, SE, SW, NW), then degrees-minutes-seconds, then distance and unit.
2. Convert bearings to azimuth. NE = the angle; SE = 180° − angle; SW = 180° + angle; NW = 360° − angle. This is the step people get wrong most often.
3. Run the traverse. For each course, compute the departure (distance × sin azimuth) and latitude (distance × cos azimuth) and accumulate them. Corrected for a real spheroid it's a geodesic problem — on paper, plane math is close enough to find big errors.
4. Measure the misclosure. After the last call, the accumulated position minus the POB is your gap in feet.
5. Compute the precision ratio and compare it to the era and quality of the survey.

Why deeds fail to close (the usual suspects)

• Reference ties read as boundary calls. "From which the NE corner bears S 89° E, 611 ft" is a monument tie — a sighting to a corner — not a course of the boundary. Including it doubles the parcel.
• OCR and transcription digits. 208.61 typed where the deed says 208.66; 01°36' misread as 07°36'.
• Curves. A curve's traverse leg is the chord bearing and chord length. Using arc length, radius, or tangent distance as the course corrupts the polygon.
• Easement and exception language. A "save and except" tract or an appurtenant easement with its own courses gets swept into the main parcel.
• Malformed DMS. Values like 60°57'60" are legal — sixty seconds carry into the minutes. Some tools reject them outright.

The fast way: an automated closure audit

The Polygon Closure Auditor does the whole traverse for you. Upload a PDF, DOCX, or a phone photo of the recorded page — vision OCR extracts the calls, monument ties and exception tracts are separated out, curves fall back to chord values, and the traverse is computed geodesically on WGS84. You get the misclosure in feet and meters, the precision ratio, acreage, and a map of the parcel on real satellite imagery.

When a description fails to close, the error detective tests the common transcription errors — flipped quadrants, transposed digits, misread degrees — and points at the single call most likely to blame, so you can check it against the recorded document instead of re-running everything.

Common questions