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International Geomagnetic Reference Field (IGRF), 14th Generation Calculator

Use the tool below to compute values for the geomagnetic field and secular variation for a given set of coordinates and date. This calculator uses the International Geomagnetic Reference Field (IGRF), 14th Generation, as released in Dec 2024.

Choose the geodetic/geocentric latitude and longitude either by entering the coordinates into the form below (decimal degrees may be entered into the 'degrees' field, and degrees S or W should be entered with a negative sign), or by simply clicking the location on the map. The altitude or radius and date may be set using the appropriate form fields.

Clicking on the 'Show result on map' button will display the values for the chosen coordinates in a pop-up window. These results may be saved by clicking on the 'Save' button allowing you to compare values from a number of locations.

km above MSL
Range: 1900-2035

Legend

Model result parameters are described in the table below.

MF = Main Field SV = Secular Variation
D = Declination degrees east arcmin/year
I = Inclination degrees down arcmin/year
X = North Intensity nT nT/year
Y = East Intensity nT nT/year
H = Horizontal Intensity nT nT/year
Z = Vertical Intensity nT down nT/year
F = Total Intensity nT nT/year

As this is based on a web service you can also obtain results in XML/JSON format using an HTTP GET request. Fetch data in XML format here modifying the query string parameters as appropriate.

Learn More

The Earth's magnetic field is a vector quantity; at each point in space it has a strength and a direction. To completely describe it we need three quantities. These may be:

  • X, Y, and Z - three orthogonal strength components
  • F, D, and I - the total field strength and two angles
  • H, Z, and D - two strength components and an angle

The relationship between these 7 elements can be viewed at: INTERMAGNET

Secular variation (SV) is typically defined as the slow annual to decadal change of the Eath's magnetic field and is caused by the flow of liquid in the outer core, deep inside the Earth. The change of the field is not easily predictable due to the nature of the flow regime in the core and the mechanism by which the magnetic field is generated. However, an estimate of the instantaneous flow itself can be computed, if we make some assumptions about its nature and how it affects the magnetic field we observe at the surface. If we have a longer series of data we can compute the accelerated flow too.