Blog · September 30, 2026
What Is an Azimuth on a Survey?
An azimuth is a direction measured as a full-circle angle, usually clockwise from north, from 0 to 360 degrees. A bearing is a quadrant angle, such as north 30 degrees east. They can describe the same line, and mixing the two notations reverses courses.
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Full circle versus quadrant
Bearings split the compass into four quadrants and never exceed 90 degrees. North 30 degrees east is 30 degrees east of north. South 30 degrees west is the opposite direction, 180 degrees away in direction of travel along the same straight line if you are talking about the line’s two ends, which is a separate caution. Azimuths run the whole way around. An azimuth of 30 degrees is the same direction as north 30 degrees east, if both are measured from the same north. An azimuth of 210 degrees is the opposite direction. If a deed says azimuth and you plot it as a bearing, or the reverse, the line leaves the page in the wrong direction. Read the word the document uses before you touch a protractor.
Which north, and which direction of travel
Azimuths on a survey are tied to the same basis-of-bearing problem as any other direction. Grid azimuth, geodetic azimuth, and magnetic azimuth are not interchangeable. Also notice whether the azimuth is the direction of the course as you travel it. The azimuth from A to B and the azimuth from B to A differ by 180 degrees on a straight line. A plat curve table may list a chord azimuth. That is the direction of the chord, not a license to ignore the curve. When you convert for your own sketch, write the original notation beside the conversion. Software that wants bearings will happily ingest an azimuth as if the letters N and E were hiding in it. They are not.
A desk conversion, not a stakeout
You can convert between a bearing and an azimuth on paper so you understand a note. The conversion is arithmetic. It does not put you on the line. A phone compass that shows an azimuth is a coarse magnetic instrument with local interference from a truck, a rock, or the phone itself. It is not a survey. Do not walk an azimuth from a deed with it and set a fence. County GIS may let you measure a display azimuth of a parcel edge. That azimuth is a property of the drawn polygon in that projection, not the deed’s azimuth. Platbookmapper does not convert bearings or draw the line. If the direction must be marked, a surveyor uses the basis the plat names and the monuments the plat calls.
What to do next
- See whether the document says azimuth or bearing.
- Confirm the north it is measured from.
- Remember that reversing direction on a line adds 180 degrees to an azimuth.
- Keep chord azimuths attached to the curve they belong to.
The mix-up to avoid
Reading an azimuth of 200 degrees as a bearing of 200 degrees. Bearings stop at 90. A three-digit direction is a clue you are in azimuth country, and plotting it as a quadrant bearing turns the course around.
Questions people ask
Is north always zero azimuth?
Usually, in land surveying, azimuths are reckoned from north. Some older engineering work reckoned from south. The note should say. If it says from south, zero is south and the whole circle rotates in meaning. Do not assume.
Do I need azimuths to read a normal lot plat?
Most house-lot plats speak in bearings. You need azimuths when the sheet or the deed uses them, which is common in some coordinate surveys and in curve tables. If you only see quadrant letters, stay with bearings.
Find the county map
Start at Platbookmapper, search the county, and open the local GIS link. Write down the parcel number before you compare the screen to a paper plat.
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey.