Hair
70 µm - Diameter; example.
A hair is a slender strand of protein that grows from the skin of humans and other mammals.
A 70 µm diameter example; hair thickness varies.
Defined examples — our methodologyThe diameter of a hair is about 9.33 times the characteristic size of a red blood cell. Selected basis: an example for Hair; a representative value for Red blood cell; approximate values.
The ring marks the true-scale position of a red blood cell; it does not show its width. Only the inset is enlarged (×59.7).
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions. Horizontal rulers compare the selected spans; vertical brackets also identify height on the artwork.
70 µm - Diameter; example.
A hair is a slender strand of protein that grows from the skin of humans and other mammals.
A 70 µm diameter example; hair thickness varies.
Defined examples — our methodology7.5 µm - Characteristic size; representative.
A red blood cell is a specialised blood cell that transports oxygen using haemoglobin. Mature human red blood cells are flexible, disc-shaped cells.
A chosen 7.5 µm human red-blood-cell diameter. Real cells vary and deform.
University of Utah — Cell size and scaleThere’s always another scale
Side by side

Illustrative artwork · not to scale
Illustrative artwork · not to scale
Illustrative artwork · not to scale
Illustrative artwork · not to scaleGot a good eye for scale?