A ship's captain, a pilot and a hill walker with a compass all describe direction the same way: with a bearing. And any map you have ever used is a scale drawing — real distances shrunk down so a whole country fits on a page. This chapter covers both, plus the handy trick for finding the bearing back the way you came.
Three-figure bearings
A bearing is the angle measured clockwise from North, and it is always written with three figures — think of it like a three-digit combination lock, so 45° becomes 045°.
- North = 000° · East = 090° · South = 180° · West = 270°.
- An angle of 45° is written 045° — pad with a leading zero. An angle of 9° becomes 009°.
| Direction | Bearing |
|---|---|
| North | 000° |
| East | 090° |
| South | 180° |
| West | 270° |
Back bearings
The bearing back the way you came is found with ±180°: add 180 if the bearing is under 180, subtract 180 if it is over. It works because turning to face home is exactly a half-turn (180°) from your outward direction.
Scale drawings
A scale like 1 cm : 5 km means every 1 cm on the drawing is 5 km in real life. To go from drawing to real life you multiply; to go from real life back to the drawing you divide.
In a nutshell: bearings are clockwise from North and always three figures; back bearing = the original ±180°; scale drawings convert by multiplying (to real) or dividing (to drawing) with the given ratio.