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Putting sizes in perspective

Virus and bacterium: comparing T4 and E. coli

T4 and E. coli are two named examples, not two universal dimensions. This comparison concerns their representative lengths; other viruses or bacteria may be very different.

Escherichia coli: a dimension about 10 times that of Bacteriophage T4 using the adopted values.

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What is the size difference between a virus and a bacterium?

Dimensions adopted for the calculation
ReferenceDimension
Bacteriophage T4200 nm
approximate length
Escherichia coli2 µm
Representative length

Calculation: 2 µm ÷ 200 nm, after conversion into the same unit. The ratio calculated from the catalogue data is about 10.

Both illustrations use a common factor for the stated dimension. Positions aid reading and do not represent physical separation.

Check the conventions

Bacteriophage T4

A head and tail allow this virus to infect certain bacteria. Displayed dimension: approximate length.

Catalogue value to check against the source; not individually audited.

Escherichia coli

A rod-shaped bacterium whose size depends on its growth conditions. Displayed dimension: representative length.

Catalogue value to check against the source; not individually audited.

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Replace an object in the explorer, keep the common scale factor and try predicting the new ratio before reading it.

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