High-speed mechanical agitation is commonly used to produce microbubbles and droplets for ultrasound imaging and therapy. This technique results in a high concentration (~1010 particles/mL) of polydisperse particles (less than 400 nm to greater than 15 μm in diameter). Differential centrifugation has been used to isolate microbubbles and droplets of specific sizes. In our prior work, we have isolated droplets between 2 μm and 5 μm. In the current work, we have isolated different sizes of droplets by adjusting centrifugation speeds. Our size-isolation protocol increased the fraction of droplets between 1 μm and 3 μm from 8% for non-centrifuged droplets to 87% for differentially centrifuged droplets. An empirical model for the size distribution after differential centrifugation was developed. The measured fraction of droplets in the supernatant and pellet for all sizes after a single centrifugation was used in the empirical model. There was a 3% difference in the volume-weighted mean diameter of the experimentally measured and empirically modeled size distributions. The coefficient of variations of the experimentally measured and empirically modeled size distributions were 24% and 22%, respectively. The empirical model allows for determining appropriate centrifugation parameters to obtain desired size distributions. [Work supported in part by NIH grant KL2 T78.]