Magnetic declination calculator

An updated IGRF model is expected at the end of 2014 and it will be incorporated when it becomes available. The IGRF-2010 model is intended for use up to the end of 2014. Values computed with the IGRF-2010 for 2015 may be of reduced accuracy. Note that there will be slight differences between the current IGRF-2010 and expected IGRF-2015 results especially for the time period of 2009 to 2015.

Information: Date

The range of dates permitted with the International Geomagnetic Reference Field (IGRF-2010) ranges from 1900 and 2015. An updated model is expected to be implemented by January 2015.

Information: Latitude and Longitude

When entering the geographic latitude or longitude use one of the following three conventions:

  • Decimal degrees to a maximum of three decimal places, e.g., 45.738. Choose North or South, East or West from the 'radio' buttons.
  • Degrees and minutes, e.g. 45 54.3. Choose North or South, East or West from the 'radio' buttons.
  • Degrees, minutes, and seconds, e.g. 45 54 3.3. Input seconds will be rounded to the nearest second in the output. Choose North or South, East or West from the 'radio' buttons.
Information: Grid declination

Grid Declination is defined as the angle between magnetic North and grid North where grid North is referenced to the grid lines shown on navigation charts. The convergence angle is also supplied when grid declination is selected. The convergence angle is the angle between grid North and True North.

For more information on grid declination and the convergence angle, please refer to the following pages:

This calculator may be used to calculate the magnetic declination for a specified location and date based on the International Geomagnetic Reference Field model.

Learn how to use the magnetic declination with a compass.

Other components of the magnetic field may be calculated using the magnetic field calculator.