The program density-fitness calculates electron density metrics, for main- (includes Cβ atom) and side-chain atoms of individual residues. For this calculation, the program uses the structure model in either PDB or mmCIF format and the electron density from the 2mFo-DFc and mFo-DFc maps. If these maps are not readily available, the MTZ file and model can be used to calculate maps clipper. Density-fitness support both X-ray and electron diffraction data. This program is essentially a reimplementation of edstats, a program available from the CCP4 suite. However, the output now contains only the RSR, SRSR and RSCC fields as in edstats with the addition of EDIAm and OPIA and no longer requires pre-calculated map coefficients.