Microscopic · #999 biggest of 1,014
How big is a smallpox virus?
300 nm
A smallpox virus measures 300 nm. That's about 3 viruses lined up end to end.
By the numbers
- That's 300 nanometers (nm) — smaller than a wavelength of visible light.
- You'd need about 5.67 million of them stacked up to reach the height of an average adult.
- Roughly 3,000 atoms could line up across it.
- Out of all 1,014 things in this collection, it ranks #999 by size.
Size comparison
How smallpox virus stacks up against things of a similar size. Tap any bar to explore it.
bacterium (E. coli)
2.0 µm
mitochondrion
1.0 µm
wavelength of red light
7.0e+2 nm
wavelength of blue light
4.5e+2 nm
smallpox virus
3.0e+2 nm
HIV virus
1.2e+2 nm
influenza virus
1.0e+2 nm
coronavirus
1.0e+2 nm
ribosome
20 nm
Bars use a logarithmic scale so everything fits — real differences are even more extreme!
Fun fact
It's so small that about 3,333 of them would fit across a single millimeter.
More in Microscopic
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