*Estimated value
SARS-CoV-2 and variants, SARS-CoV and MERS-CoV: 0.1 microns, Influenza A (H1N1): 0.08 microns, Klebsiella pneumoniae and Staphylococcus aureus: 0.5 microns, Escherichia coli: 0.25 microns, Candida albicans: 2 microns
1 cm (centimetres) = 10 mm (milimetres) = 10,000 μm (micrometres) = 10,000,000 nm (nanometres)