Virus
A virus is an infectious particle containing genetic material inside a protein coat, sometimes with an outer envelope. It reproduces only inside host cells.
How big is it?
100 nm across
Characteristic size · representative
A little perspective
About the same scale as Influenza virion.
Influenza virion: An influenza virion is a single infectious particle of the influenza virus, consisting of genetic material inside a lipid envelope.
Measurements, assumptions & sources +
Virus
A chosen 100 nm viral particle, including the approximate envelope. Viruses vary greatly.
University of Utah — Cell size and scale
The marked characteristic size is calibrated. Unmeasured illustration details are representative.
Influenza virion
A representative 100 nm enveloped influenza particle. Shape and size vary, and surface proteins extend beyond the selected envelope diameter.
The marked representative envelope diameter is calibrated. Unmeasured illustration details are representative.
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Why this measurement?
Why we use 100 nm
For comparison, this page uses characteristic size. This is labelled representative; the central value is useful for comparison, while real values or measurement solutions can vary.
A chosen 100 nm viral particle, including the approximate envelope. Viruses vary greatly.
The marked horizontal span follows the named feature; transparent margins and unmeasured details do not alter it. How calibrated comparisons work →
Recorded properties
Virus dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 100 nm | Not recorded | representative | |
| 1 × 10⁻¹⁸ kg | Not recorded | defined specimen |
Around this scale
Go smaller. Go bigger.
These links use compatible length records, ordered around the selected value.
Nearest lower value · MicroscopicRibosome25 nmA ribosome is a molecular machine that builds proteins by reading instructions carried by messenger RNA.
Around the same scale · MicroscopicInfluenza virion100 nmAn influenza virion is a single infectious particle of the influenza virus, consisting of genetic material inside a lipid envelope.
Nearest higher value · MicroscopicBacteriophage T4200 nmBacteriophage T4 is a virus that infects bacteria.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- University of Utah — Cell size and scaleApproximate biological size regimes. Atlas specimens and geometric assumptions are individually labelled.
- Defined examples — our methodology
More ways to see it
Curated comparisons
There’s always another scale
Follow your curiosity.
Fundamental physicsProton1.682 fmA proton is a positively charged particle found in the nucleus of atoms, made up of quarks.
Microscopic10 µm cell10 µmA cell is the basic structural unit of living organisms.
People70 µm hair70 µmA hair is a slender strand of protein that grows from the skin of humans and other mammals.MicroscopicInfluenza virion100 nmAn influenza virion is a single infectious particle of the influenza virus, consisting of genetic material inside a lipid envelope.MicroscopicBacteriophage T4200 nmBacteriophage T4 is a virus that infects bacteria.MicroscopicRibosome25 nmA ribosome is a molecular machine that builds proteins by reading instructions carried by messenger RNA.
MicroscopicIgG antibody molecule14.5 nmAn IgG antibody molecule is a Y-shaped protein produced by the immune system to identify and neutralise foreign substances.
Microscopic2 µm bacterium2 µmA bacterium is a single-celled microorganism without a membrane-bound nucleus.