A pair of empirical equations are proposed for the purpose of approximating the dynamic mechanical viscoelasticity functions, the storage compliance, J′(ω), and the nonviscous loss compliance, J″(ω)−1/ωη, from the value of the recoverable compliance, Jr(t), and its logarithmic slope, m(t)=d log Jr(t)/d log t. The angular frequency is ω and the shear viscosity is η. Three examples representing various kinds of polymeric, viscoelastic response are presented as tests of the effectiveness of the proposed expressions. Most of the calculated points are in error by less than 10%.