Red blood cell
A red blood cell is a specialised blood cell that transports oxygen using haemoglobin. Mature human red blood cells are flexible, disc-shaped cells.
How big is it?
7.5 µm · characteristic size
Characteristic size · representative
A little perspective
Red blood cell vs Dust particle: length comparison
The characteristic size of a dust particle is about 1.33 times the characteristic size of a red blood cell.
A red blood cell is a specialised blood cell that transports oxygen using haemoglobin.
Dust is a mixture of tiny solid particles from sources such as soil, fibres, skin and pollen.
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions.
Measurements, assumptions & sources +
Red blood cell
Characteristic size: 7.5 µm; representative.
A chosen 7.5 µm human red-blood-cell diameter. Real cells vary and deform.
University of Utah — Cell size and scale
The marked characteristic size is calibrated. Unmeasured illustration details are representative.
Dust particle
Characteristic size: 10 µm; representative.
A chosen 10 µm particle. Dust is a mixture, not a single size or material.
University of Utah — Cell size and scale
The marked characteristic size 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 7.5 µm
We compare the characteristic size of a red blood cell. This is a representative comparison value; individual specimens or conditions can vary.
A chosen 7.5 µm human red-blood-cell diameter. Real cells vary and deform.
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 |
|---|---|---|---|
| 7.5 µm | Not recorded | representative | |
| 100 pg | 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 objectsYeast cell5 µmCharacteristic sizeYeast is a group of single-celled fungi.
Around the same scaleMicroscopic objectsDust particle10 µmCharacteristic sizeDust is a mixture of tiny solid particles from sources such as soil, fibres, skin and pollen.
Nearest higher valueMicroscopic objectsCell10 µmDiameterA cell is the basic structural unit of living organisms.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.
Living thingsHoneybee1.5 cmA honeybee is a social insect that lives in a colony and gathers nectar and pollen from flowers.
Living thingsSmall ant5 mmAn ant is a social insect that lives in an organised colony, usually with workers, a queen and specialised roles.
Everyday thingsUS quarter2.426 cmA US quarter is a coin worth twenty-five cents, commonly used in United States currency.MicroscopicDust particle10 µmDust is a mixture of tiny solid particles from sources such as soil, fibres, skin and pollen.MicroscopicYeast cell5 µmYeast is a group of single-celled fungi.MicroscopicCell10 µmA cell is the basic structural unit of living organisms.
MicroscopicPlatelet3 µmA platelet is a small blood-cell fragment that helps form clots and stop bleeding after a blood vessel is damaged.
PeopleSperm cell50 µmA sperm cell is a male reproductive cell with a compact head, energy-producing midpiece and a flagellum used for movement.