Distance & Bearing Calculator

Field guide: Distance & Bearing Calculator

The 'inverse' problem — given two coordinates, find the distance and direction between them — is the computation field people reach for constantly: how far to the next pole, what bearing to walk to the corner stake, does the deed's '240 m at N 47° E' match what GPS says about the two monuments. This calculator solves it on the sphere: haversine distance (accurate to ~0.3% of true geodesic, far better than the points' GPS error) and initial whole-circle bearing from true north, plus the back bearing for the return sight.

Both ends accept live GPS capture, which turns the page into a two-tap rangefinder between any two places you can stand. The bearing nuance worth knowing: results are TRUE bearings (geographic north); a magnetic compass needs your local declination applied, and long lines have a continuously changing bearing (the 'initial' bearing is exact at point A). For plane-survey work on projected grids, grid convergence separates these true bearings from grid bearings by a small, knowable angle.

Field tips

• Compass users: apply local magnetic declination (true bearing − declination = magnetic, east declination positive) — it ranges from ~0.5°E to 1°+ across India and much more elsewhere.
• Back bearing = forward ± 180° exactly on the sphere only for short lines; the displayed value is the practical return bearing for field distances.
• Capture both points in open sky and the distance error is dominated by GPS (±3–5 m per point), not the formula.

Records are stored only in this browser (localStorage) — export regularly. This tool aids field documentation; it does not replace your agency's official inspection procedures or engineering judgment.