This paper presents a new single crystal neutron scattering data analysis program, Mufit. The program can be used to refine spherical neutron polarimetry (SNP) data as well as nuclear and magnetic single crystal diffraction data. The article presents a brief overview of the SNP process and the core mathematics used to calculate the SNP matrices and gives an example of data that has been fitted using the MuFit package, which is available on request from the author: Bertrand.Roessli@psi.ch.