Micro World

How big are microscopic things? 85 sizes compared

The largest thing on this page is about 15 million times the size of the smallest. A carbon atom is about 0.34 nm across, while a colony of the cyanobacterium Nostoc is about 5 mm (0.2 in) wide, big enough to see without a microscope. Between them are sugar and chlorophyll molecules, viruses such as the giant Mimivirus at about 750 nm, bacteria, spores, pollen grains and human cells. A human B lymphocyte, one of the white blood cells, is about 7 µm across, and the giant amoeba Chaos carolinense stretches to about 1 mm. Sizes this small are hard to picture, so the drawing below zooms out in steps and marks how far each step zooms. Every size is for one typical example, as its source measures it.

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Micro World, from Carbon Atom to Nostoc Colony, drawn to scale — Drawn to scale, from left to right: Carbon Atom (0.34 nm), Bacteriorhodopsin Molecule (5 nm), Silica Nanoparticle (100 nm), Nitrosomonas europaea Bacterium (1.5 µm), HeLa Cell (20 µm), Human Purkinje Cell (250 µm) and Nostoc Colony (5 mm). Each panel zooms out from the one before it (×280, ×170 and ×19); the faint shape at the start of a panel is the largest object of the previous one.

Sizes in Micro World

All 85 microscopic things on this page, from the smallest to the largest. Each size is in metric units first, with imperial in brackets where it differs.

Name	Size
Carbon Atomdiameter	0.34 nm
Ozone Moleculediameter	0.35 nm
Sucrose Moleculelength	1 nm
Single-Walled Carbon Nanotubediameter	1.4 nm
Chlorophyll Moleculelength	1.7 nm
Bacteriorhodopsin Moleculediameter	5 nm
Transfer RNA Moleculelength	8 nm
Amyloid Beta Fibrilwidth	10 nm
Semiconductor Quantum Dotdiameter	10 nm
Nucleosomediameter	11 nm
Ferritin Moleculediameter	12 nm
Colloidal Gold Nanoparticlediameter	20 nm
Bacteriophage Phi X174diameter	27 nm
Qβ Bacteriophagediameter	28 nm
Silver Nanoparticlediameter	40 nm
Fibrinogen Moleculelength	45 nm
Silicon Nanowirediameter	50 nm
West Nile Virusdiameter	50 nm
Human Papillomavirusdiameter	55 nm
Cyanophage P-SSP7diameter	60 nm
Silica Nanoparticlediameter	100 nm
Titanium Dioxide Nanoparticlediameter	100 nm
Lassa Virusdiameter	100 nm
Hantavirusdiameter	100 nm
Nuclear Pore Complexdiameter	120 nm
Cowpox Viruslength	250 nm
Collagen Fibrildiameter	300 nm
Vaccinia Viruslength	300 nm
Lysosomediameter	500 nm
Mimivirusdiameter	750 nm
Neisseria gonorrhoeaewidth	800 nm
Pandoraviruslength	1 µm
Synechococcus Cyanobacteriumdiameter	1 µm
Nitrosomonas europaea Bacteriumlength	1.5 µm
Micrococcus luteusdiameter	1.5 µm
Listeria monocytogeneslength	2 µm
Campylobacter jejunilength	2 µm
Klebsiella pneumoniaelength	2 µm
Deinococcus radioduransdiameter	2 µm
Shigella flexnerilength	2.5 µm
Penicillium Sporediameter	3 µm
Aspergillus niger Sporediameter	4 µm
Clostridium difficilelength	4 µm
Cryptosporidium parvum Oocystdiameter	5 µm
Chlorella Algae Celldiameter	5 µm
Candida albicansdiameter	5 µm
Halobacterium salinarumlength	5 µm
Thermus aquaticuslength	5 µm
Human T Lymphocytediameter	7 µm
Human B Lymphocytediameter	7 µm
Cryptococcus neoformansdiameter	8 µm
Human Melanocytediameter	8 µm
Human Natural Killer Celldiameter	10 µm
Human Pancreatic Beta Celldiameter	10 µm
Rhizopus Sporediameter	10 µm
Human Basophildiameter	12 µm
Human Dendritic Celldiameter	15 µm
Trichomonas vaginalislength	15 µm
Human Astrocytediameter	15 µm
Human Kupffer Celldiameter	15 µm
Human Chondrocytediameter	15 µm
HeLa Celldiameter	20 µm
Cellulose Fiberdiameter	20 µm
Human Erythroblastdiameter	20 µm
Human Goblet Cellheight	20 µm
Thalassiosira Diatomdiameter	20 µm
Human Hepatocytediameter	25 µm
Human Osteocytediameter	25 µm
Dandelion Pollen Graindiameter	35 µm
Taenia solium Eggdiameter	35 µm
Tetrahymena thermophilabody length	50 µm
Ascaris lumbricoides Egglength	60 µm
Human Cheek Epithelial Cell	60 µm
Pine Pollen Grainwidth	70 µm
Human Adipocytediameter	100 µm
Euplotesbody length	100 µm
Human Cardiomyocytelength	100 µm
Human Smooth Muscle Celllength	100 µm
Onion Epidermal Cellwidth	100 µm
Didiniumbody length	150 µm
Coscinodiscus Diatomdiameter	150 µm
Human Purkinje Cellheight	250 µm
Blepharisma japonicumbody length	300 µm
Chaos carolinenselength	1 mm
Nostoc Colonydiameter	5 mm (0.2 in)

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Play Micro World in Magnitudle

5 levels of Micro World in the app: 5 hard.

Levels include “Cells and Viruses Unseen”, “Tiny Particles Tiny Life” and “Hidden World Showdown”.

In each level you guess sizes before you see them: resize a silhouette to scale, rank things by size or pick the biggest.

Scan with your iPhone camera to get the app

Scan with your Android phone to get the app

Levels, the daily challenge and live duels are all in the app: Magnitudle for iPhone.

Test your sense of scale

Tap the biggest one

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