What is the size (diameter) of the SARS-CoV-2 virus?
Electron micrographs of negative-stained 2019-nCoV particles were generally spherical with some pleomorphism (Figure 3). Diameter varied from about 60 to 140 nm. Virus particles had quite distinctive spikes, about 9 to 12 nm, and gave virions the appearance of a solar corona.


--A Novel Coronavirus from Patients with Pneumonia in China, 2019

Figure 3 from that article: