1. What is Back Bearing?

Back bearing is the opposite direction of a given bearing in navigation. It's used when you need to return along the same path you came from, or when determining reciprocal directions in surveying and mapping.

2. How to Calculate Back Bearing

The back bearing is calculated using a simple formula:

Explanation:

• If the original bearing is less than 180°, add 180° to get the back bearing
• If the original bearing is 180° or more, subtract 180° to get the back bearing
• The result is always between 0° and 360°

3. Practical Applications

Navigation: Back bearings are essential for return trips, verifying positions, and maintaining course direction in land navigation, marine navigation, and aviation.

4. Using the Calculator

Instructions: Enter the original bearing in degrees (0-360) and click calculate. The calculator will automatically determine whether to add or subtract 180° based on your input.

5. Frequently Asked Questions (FAQ)

Q1: What if my bearing is exactly 180°?
A: The back bearing would be 0° (360°), as 180° - 180° = 0°.

Q2: How precise should my bearing measurement be?
A: For most navigation purposes, bearings are measured to the nearest degree. More precise measurements may be needed for surveying.

Q3: Does this work for magnetic bearings?
A: Yes, the same calculation applies whether you're using true north or magnetic north bearings.

Q4: What about bearings in mils or grads?
A: This calculator uses degrees. For mils (6400 in a circle) or grads (400 in a circle), you would add/subtract 3200 mils or 200 grads respectively.

Q5: Why is back bearing important in navigation?
A: It helps ensure you can return along your original path and is used for position fixing techniques like resection.