geoprimsField-grade geospatial math

Inverse between two coordinates

The bearing, azimuth, and horizontal distance between two plane-survey coordinates (northing, easting).

Go the other way: Coordinates from a bearing and distance →

Experimental: not yet fully verified. How results are checked

N 45°00'00" E

The bearing is N 45°00'00" E and the distance is 141.421 ft.

Distance
Azimuth
Provenance
Computed by
survey.cogo.inverse 1.0.0, core 0.1.0
Model
Plane coordinate geometry: azimuth = atan2(ΔE, ΔN), distance = √(ΔN² + ΔE²)
Accuracy
Exact for the plane (grid or assumed) coordinates given
Notes
1 shown with the answer
Cites
Ghilani, C. D., and Wolf, P. R., Pearson, Elementary Surveying: An Introduction to Geomatics

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How we got thisFormula, worked example, sources, and proof

Model: Plane coordinate geometry: azimuth = atan2(ΔE, ΔN), distance = √(ΔN² + ΔE²)

Accuracy: Exact for the plane (grid or assumed) coordinates given

Worked example: From (1,000, 1,000) to (1,100, 1,100). Source: add-survey-suite scenario: N 45°00'00" E, 141.421. It is golden test vector v001, and every build checks the tool still gives its answer within its tolerance.

You enter

From easting
1000 ft
To easting
1100 ft
From northing
1000 ft
To northing
1100 ft

You get

Bearing
N 45°00'00" E
Distance
141.421 ft
Azimuth
45°

Review: Not yet independently reviewed by a licensed surveyor.

Last verified: 2026-09-23, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.

Status: version 1.0.0, core 0.1.0. See this tool in the verification report.

Checked against: 6 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.

Sources

Experimental means this tool has not yet met the stable bar: at least 20 golden vectors, differential tests, and an independent worked example.