The Swarm-Echo Satellite carries two magnetometers that allow us to obtain two independent measurements of the changes that occur in the Earth's magnetic field during events such as aurora. Magnetometers must be independently calibrated to ensure they remain accurate. If no magnetic reference is available, a model magnetic field must be used. This paper discusses the method used to calibrate the magnetometers on Swarm-Echo and shows the improvements the calibration has made to the data product.