1. What is Grid Magnetic Angle?

The Grid Magnetic Angle (GMA) is the angular difference between Grid North and Magnetic North. It's used in navigation and mapping to convert between grid bearings and magnetic bearings.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• Grid North — The north direction of the grid lines on a map
• Magnetic North — The direction a compass needle points (magnetic pole)

Explanation: The calculation shows how much you need to adjust between grid references and magnetic compass readings.

3. Importance of Grid Magnetic Angle

Details: This angle is crucial for accurate navigation, especially in areas with significant magnetic declination. It's used by surveyors, military personnel, and outdoor enthusiasts.

4. Using the Calculator

Tips: Enter both Grid North and Magnetic North values in degrees. The values can be positive or negative depending on your location relative to the prime meridian.

5. Frequently Asked Questions (FAQ)

Q1: How often does the magnetic angle change?
A: Magnetic north moves over time, so the angle should be updated periodically (typically annually for precise work).

Q2: What's the difference between grid north and true north?
A: Grid north is the map's coordinate system north, while true north points to the geographic North Pole.

Q3: Where can I find grid north for my area?
A: Grid north is typically shown on topographic maps or can be calculated from the map's coordinate system.

Q4: How does this relate to magnetic declination?
A: Grid magnetic angle is similar to magnetic declination but specific to the map grid system being used.

Q5: When is this angle most important?
A: Critical when converting between map bearings and compass bearings over long distances or when precision is required.