This report provides a comprehensive description of the World Magnetic Model (WMM) 2025 and its higherresolution version, the World Magnetic Model – High Resolution (WMMHR) 2025. Section 1 contains informationthat users of WMM2025 and WMMHR2025 require to implement the model and software in navigation andheading systems, and to understand magnetic charts, poles and geomagnetic coordinate systems. Section 2presents a detailed summary of the data used and the modeling techniques employed. Section 3 assesses modeluncertainties and describes the error models associated with WMM2025 and WMMHR2025. Section 4 providescharts of all the magnetic elements at 2025.0 and their projected annual rates of change between 2025.0 and2030.0 based on WMM2025. These predictions are derived from the best knowledge of the geomagnetic mainfield evolution at the time the WMM was released.Sponsored by the U.S. National Geospatial-Intelligence Agency (NGA) and the U.K. Defence Geographic Centre(DGC), the World Magnetic Model (WMM) and the World Magnetic Model – High Resolution (WMMHR) areproduced by the U.S. National Oceanic and Atmospheric Administration’s National Centers for EnvironmentalInformation (NOAA NCEI) and the British Geological Survey (BGS). The WMM is the standard model used by theU.S. Department of Defense (DoD), the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO)and the International Hydrographic Organization (IHO), for navigation, attitude and heading referencing systemsusing the geomagnetic field. It is also used widely in civilian navigation and heading systems.The WMM2025 and WMMHR2025 product release includes downloadable software tools and online calculatorsthat enable the computation of both models and/or the integration of their subroutines into larger DoD systems.The provided software is designed to support various aspects of DoD systems procurement and development.All users are encouraged to use WMMHR in systems able to support the additional coefficients. WMMHR isexpected to outperform WMM in most practical applications, and WMM should be implemented only in legacysystems unable to ingest the additional coefficients. See Section 3.3 for more details.