Scale Explorer

Microscopic

How big is a coronavirus particle?

Coronavirus (SARS-CoV-2) · SARS-CoV-2, the virus that causes COVID-19 · Severe acute respiratory syndrome coronavirus 2

Particle diameter
60–140 nm 60–140 nm range
Mean diameter (Omicron BA.1 to BA.2)
75–81.5 nm 75–82 nm range
Spike protein diameter
9–12 nm 9–12 nm range
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Coronavirus (SARS-CoV-2), Red blood cell, Human hair (width), Human drawn to the same scaleCoronavirus (SARS-CoV-2): particle diameter 60–140 nm (too small to see at this scale). Red blood cell: diameter 7.5–8.7 µm (too small to see at this scale). Human hair (width): average diameter ≈ 70 µm (too small to see at this scale). Human: height 1.61–1.75 m.Coronavirus (SARS-CoV-2): 60–140 nm (too small to see at this scale)Red blood cell: 7.5–8.7 µm (too small to see at this scale)Human hair (width): ≈ 70 µm (too small to see at this scale)Human: 1.61–1.75 mHuman1.61–1.75 mCoronavirus (SARS-CoV-2)60–140 nm · too small to seeRed blood cell7.5–8.7 µm · too small to seeHuman hair (width)≈ 70 µm · too small to see

Coronavirus (SARS-CoV-2), Red blood cell and Human hair (width) are too small to see at this scale and are marked with ▲.

Everything is drawn to the same scale, standing on the same ground line. Silhouettes are simplified outlines scaled to the measured dimension. A faded outline shows the top of a size range.

Compare Coronavirus (SARS-CoV-2) with something else →

Dimensions

MeasurementMetricImperialNotesSource
Particle diameter 60–140 nm 60–140 nm Range from early electron-microscope observations of the virion. Range: varies [1]
Mean diameter (Omicron BA.1 to BA.2) 75–81.5 nm 75–82 nm Mean diameters from cryo-electron tomography: BA.1 75.0 +/- 7.9 nm, BA.2 81.5 +/- 6.6 nm. Range: varies [2]
Spike protein diameter 9–12 nm 9–12 nm Width of the spike proteins projecting from the envelope. Range: varies [1]

About the coronavirus particle

SARS-CoV-2 is the coronavirus behind the COVID-19 pandemic. Under the electron microscope its particles look roughly round, studded with spike proteins that give the family its crown-like appearance. Early imaging measured the particles at about 60 to 140 nm across, and later cryo-electron studies of Omicron sublineages found average diameters of about 75 to 82 nm.

  • Cryo-electron tomography counted on average about 23 pre-fusion spikes on each Omicron BA.1 particle and about 35 on each BA.2 particle, compared with about 26 reported for the original virus. [2]
  • The Omicron BA.1 and BA.2 particles were found to be similar in size to the original (wild-type) virus grown in the same cells. [2]

How many fit?

  • ≈ 12 million–29 million × Coronavirus (SARS-CoV-2) · particle diameter lined up end to end match the Human · height
  • ≈ 54–140 × Coronavirus (SARS-CoV-2) · particle diameter lined up end to end match the Red blood cell · diameter

Counts divide one sourced figure by another. "End to end" uses each object's main measurement; weight and volume rows appear only when both figures are sourced.

How it compares

  • 1/54–140 A red blood cell is about 54–140 times as across as a coronavirus particle. See side by side
  • 1/500–1,200 The width of a human hair is about 500–1,200 times as wide as a coronavirus particle is across. See side by side
  • 1/450–33,000 A grain of sand is about 450–33,000 times as wide as a coronavirus particle is across. See side by side
  • 1/24,000–83,000 A black garden ant is about 24,000–83,000 times as long as a coronavirus particle is across. See side by side
  • 1/47,000–120,000 A grain of rice is about 47,000–120,000 times as long as a coronavirus particle is across. See side by side
  • 1/12 million–29 million An average adult is about 12 million–29 million times as tall as a coronavirus particle is across. See side by side

Factors compare the particle diameter of a coronavirus particle with each object’s own main measurement (height for a human). Where a size varies, the factor is given as a range.

Notes on these figures

  • No CDC, NIH or NIAID web page stating the particle size could be fetched (NIAID returned 403 and PubMed returned a CAPTCHA), so sizes come from peer-reviewed papers hosted on NIH's PubMed Central.
  • Particles are pleomorphic (not perfectly round), and measured size depends on variant, preparation and imaging method.
  • No sourced mass or volume was found.

Sources

  1. Osong Public Health and Research Perspectives (via PubMed Central, NIH), SARS-CoV-2 in brief: from virus to prevention (Karami, Karimi, Karami, 2022). Accessed 25 September 2026.
  2. Signal Transduction and Targeted Therapy (via PubMed Central, NIH), Structural characteristics of the SARS-CoV-2 Omicron lineages BA.1 and BA.2 virions (Ma et al., 2023). Accessed 25 September 2026.

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