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 · characteristic size
Characteristic size · representative
A little perspective
Virus vs Influenza virion: length comparison
The characteristic size of a virus is approximately equal to the envelope diameter of an influenza virion.
A virus is an infectious particle containing genetic material inside a protein coat, sometimes with an outer envelope.
An influenza virion is a single infectious particle of the influenza virus, consisting of genetic material inside a lipid envelope.
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions.
Measurements, assumptions & sources +
Virus
Characteristic size: 100 nm; representative.
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
Representative envelope diameter: 100 nm; representative; range 80 nm–120 nm.
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.
Use the visual comparison to explore its scale, then check the measurements and sources.
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Why this measurement?
Why we use 100 nm
We compare the characteristic size of a virus. This is a representative comparison value; individual specimens or conditions can vary.
A chosen 100 nm viral particle, including the approximate envelope. Viruses vary greatly.
The marked horizontal span follows the measured feature, not the edges of the image. How calibrated comparisons work →
Recorded properties
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
Explore nearby values.
Compare examples with lower, similar and higher values. Each card names the measurement being compared.
Nearest lower valueMicroscopic objectsRibosome25 nmCharacteristic sizeA ribosome is a molecular machine that builds proteins by reading instructions carried by messenger RNA.
Around the same scaleMicroscopic objectsInfluenza virion100 nmRepresentative envelope diameterAn influenza virion is a single infectious particle of the influenza virus, consisting of genetic material inside a lipid envelope.
Nearest higher valueMicroscopic objectsBacteriophage T4200 nmHead-to-tail lengthBacteriophage 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.
MicroscopicCell10 µmA cell is the basic structural unit of living organisms.
PeopleHair70 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.
MicroscopicBacterium2 µmA bacterium is a single-celled microorganism without a membrane-bound nucleus.A closer look