Curie's Law Calculator

Curie's law describes the magnetic response of an ideal paramagnetic material. It states that magnetic susceptibility equals the material's Curie constant divided by absolute temperature. The model captures a key physical trend: thermal agitation increasingly randomizes magnetic moments as temperature rises, so susceptibility falls. At lower temperatures the moments align more readily with an applied field, giving a larger response, provided the material remains in the paramagnetic regime. This calculator first evaluates susceptibility using C divided by T. It then multiplies susceptibility by magnetic field strength H to estimate magnetization M. With dimensionless SI volume susceptibility and field strength in amperes per meter, magnetization is reported in amperes per meter. Temperature must be entered in kelvins because the inverse relation uses an absolute thermodynamic scale. Celsius values cannot be substituted directly; convert them by adding 273.15. The Curie constant incorporates microscopic information including the number density and effective magnetic moment of the magnetic particles. Its numerical value and units depend on whether susceptibility is expressed per volume, per mass, or per mole and on the electromagnetic unit system. The calculator follows the simple dimensionless SI volume-susceptibility convention. A constant taken from a source using cgs units or molar susceptibility must be converted before it can be combined consistently with the displayed inputs. Curie's law assumes independent localized moments and a magnetic field weak enough for a linear response. Many real materials exhibit interactions between moments. The Curie-Weiss law accounts for those interactions approximately by replacing temperature with temperature minus a fitted Curie-Weiss temperature. Near magnetic ordering transitions, at very low temperatures, or in strong fields approaching saturation, the basic inverse-temperature law can be inaccurate. Diamagnetic background and temperature-independent paramagnetism may also need to be removed from measured data. Use the result to explore trends, check classroom calculations, or estimate a weak-field paramagnetic response. For laboratory analysis, document the susceptibility convention, field definition, sample geometry, demagnetizing correction, and unit conversions. Compare calculations with measurements across a temperature range rather than relying on one point. The calculator intentionally reports both susceptibility and magnetization so the material property and its predicted response to the entered field remain clearly distinguished.