A set of formulas emphasizing accuracy was developed to describe raindrops' and ice particles' fall speed for use in multi-moment microphysical parameterizations applying gamma-type size distributions. The formulas considered fall speed's variation with particle properties (size, density, and shape) and air density based on a robust theoretical framework. Root-mean-square errors from these formulas are about 1.4% and 4%, respectively, for raindrops and ice particles. Most deviations are within ±3% for raindrops and 8% for ice particles under a wide range of particle properties and atmospheric conditions. The accuracy is significantly higher than existing formulas applied in meteorological models.One-dimensional dynamic model tests considering only the raindrop sedimentation process indicate that our formulas can properly simulate the vertical profiles of raindrops' three moments compared to the numerically integrated theoretical values. All three moments evolved consistently in time and space, with the gravitational sorting effect revealed by the faster sedimentation in the higher moments. Other less accurate formulas either misplaced the peak raindrop content's altitude or produced substantial vertical spread.