For example, consider a 1 Jy signal from a radio source at a redshift of 1, at a frequency of 1.4 GHz. Ned Wright's cosmology calculator calculates a luminosity distance for a redshift of 1 to be 6701 Mpc = 2×10 m giving a radio luminosity of 10 × 4 π (2×10) / (1 + 1) = 6×10 W Hz.