1. What is Magnetic North vs True North?

True North refers to the direction along the earth's surface towards the geographic North Pole. Magnetic North is the direction a compass points due to Earth's magnetic field. The difference between them is called magnetic declination.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• Magnetic North — Compass reading in degrees
• Declination — Angular difference between true and magnetic north
• True North — Geographic north direction

Explanation: Positive declination means magnetic north is east of true north, negative means it's west.

3. Importance of True North Calculation

Details: Accurate navigation requires understanding this difference, especially in aviation, marine navigation, and wilderness navigation where small angular differences can lead to significant errors over long distances.

4. Using the Calculator

Tips: Enter magnetic north reading from your compass and the local magnetic declination (which varies by location and changes over time). Both values should be in degrees.

5. Frequently Asked Questions (FAQ)

Q1: How do I find my local magnetic declination?
A: Use online tools from NOAA (US) or other national geological surveys. Declination changes over time and varies by location.

Q2: Does declination change over time?
A: Yes, the Earth's magnetic field changes gradually. Current declination maps should be used for precise navigation.

Q3: What's a typical declination value?
A: In the US, it ranges from about 20° east in Maine to 20° west in Washington state. Many areas have near-zero declination.

Q4: Why is this important for hikers?
A: Using a map (oriented to true north) with a compass (pointing to magnetic north) without correction can lead you significantly off course.

Q5: How often should I check declination?
A: For casual use, every few years is fine. For precise navigation, check annually as declination changes about 0.1° per year in most locations.