Bearing & Azimuth Calculator
Whole-circle bearing, quadrant bearing, grid convergence and geodesic distance between two points; the reverse computation from a bearing and distance; angle conversions; and a closed traverse from bearings and distances, with misclosure and Bowditch adjustment. Everything runs in your browser.
From (station)
To (target)
Start point
Bearing and distance
Angle / bearing converter
Degrees-minutes-seconds, decimal degrees, a quadrant bearing, gons (suffix g) or mils (suffix mil).
Included angle from three points
Enter the back station, the occupied station and the forward station as latitude, longitude pairs.
Method. Bearings between geographic coordinates are geodesic azimuths (Vincenty 1975) on the selected ellipsoid, so they are true bearings, not the flat-earth atan2 that a spreadsheet gives. The grid bearing is the same line expressed on the UTM projection: grid = true − convergence, with convergence computed from the Krüger series to sixth order. Traverse coordinates are plane computations on the entered bearings and distances, adjusted by the compass (Bowditch) rule when that box is ticked, and the enclosed area is the plane area of the adjusted figure. Verified against GeographicLib on every release — azimuths agree to 2×10⁻⁹°.
What the Bearing & Azimuth Calculator does, and how
What does the BTPL Bearing & Azimuth Calculator do?
The BTPL Bearing & Azimuth Calculator computes the whole-circle bearing, quadrant bearing, grid convergence and geodesic distance between two points, and the reverse: the coordinates reached from a start point by a bearing and distance. It also converts between angle units (degrees, gon and mil).
Can it adjust a traverse?
The BTPL Bearing & Azimuth Calculator adjusts a closed traverse: enter the observed bearings and distances and the tool reports the linear misclosure and distributes it by the Bowditch (compass) rule, giving adjusted coordinates for every station.
Is my data uploaded anywhere?
Nothing is uploaded: the BTPL Bearing & Azimuth Calculator computes its results in your own browser, and your coordinates and files are never sent to BTPL or to any other server. The optional Show on map view is the one part that needs an internet connection: it downloads the map library and the map imagery for the area on screen from third-party map servers (Esri or OpenStreetMap), which can therefore see which area is displayed. Everything else keeps working without a connection once the page has loaded.
Control, traverse and setting-out by BTPL
GNSS/RTK control networks, total-station traverses with documented closures, and setting-out for highways, railways and urban projects.