Back Bearing Calculator
Fore bearing ↔ back bearing, with the local-attraction check explained.
If FB and BB differ from 180° by more than instrument error, iron nearby is deflecting the compass — 'local attraction'. The difference tells you which station is poisoned.
Formula
Back Bearing Calculator is a free back bearing for surveyors, civil engineers and property buyers — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Back Bearing Calculator
Fore bearing ↔ back bearing, with the local-attraction check explained. The calculation implements BB = FB ± 180° (Compass traverse adjustment). If FB and BB differ from 180° by more than instrument error, iron nearby is deflecting the compass — 'local attraction'. The difference tells you which station is poisoned.
How to use Back Bearing Calculator
- 1Enter Fore bearing in °.
- 2Read Back bearing instantly — no submit button needed.
Why use Back Bearing Calculator?
- ✓Implements the standard formula — BB = FB ± 180°
- ✓Reference cited on-page: Compass traverse adjustment
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Back Bearing Calculator use?+
It computes BB = FB ± 180°, per Compass traverse adjustment. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
If FB and BB differ from 180° by more than instrument error, iron nearby is deflecting the compass — 'local attraction'. The difference tells you which station is poisoned.
Are regional land units exact?+
Conversion factors follow state revenue-department values noted on the tool. Units like bigha and katha vary by region, so always confirm the local factor named in your land records.
Is the Back Bearing Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
Related Engineering tools
Reynolds Number Calculator
Compute Re from density, velocity, pipe diameter and viscosity — with instant laminar/turbulent classification.
● LiveLaminar vs Turbulent Flow Classifier
Classify hydraulic-oil or process-fluid flow regime from kinematic viscosity, line velocity and tube bore.
● LiveBernoulli Equation Solver
Solve downstream pressure between two points from velocities, elevations and fluid density (ideal, lossless).
● Live