Scale Explorer

Microscopic

How big is a grain of sand?

Grain of sand · Sand size class on the Wentworth grade scale

Grain diameter (sand size class)
0.0625–2 mm 0.00246–0.0787 in range
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Human hair (width), Grain of sand, Ant (black garden ant), Human drawn to the same scaleHuman hair (width): average diameter ≈ 70 µm (too small to see at this scale). Grain of sand: grain diameter (sand size class) 0.0625–2 mm (too small to see at this scale). Ant (black garden ant): length (worker) 3.4–5 mm (too small to see at this scale). Human: height 1.61–1.75 m.Human hair (width): ≈ 70 µm (too small to see at this scale)Grain of sand: 0.0625–2 mm (too small to see at this scale)Ant (black garden ant): 3.4–5 mm (too small to see at this scale)Human: 1.61–1.75 mHuman1.61–1.75 mHuman hair (width)≈ 70 µm · too small to seeGrain of sand0.0625–2 mm · too small to seeAnt (black garden ant)3.4–5 mm · too small to see

Human hair (width), Grain of sand and Ant (black garden ant) 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 Grain of sand with something else →

Dimensions

MeasurementMetricImperialNotesSource
Grain diameter (sand size class) 0.0625–2 mm 0.00246–0.0787 in Nominal diameter limits of sand on the Wentworth scale; the source states the lower limit as 62.5 µm. Range: varies [1]

About the grain of sand

Geologists define sand by grain size rather than by what it is made of. On the Wentworth grade scale used by the U.S. Geological Survey, sand grains are smaller than 2.0 millimetres and larger than 62.5 micrometres across. Coarser particles count as gravel, and finer ones as silt or clay.

  • On the Wentworth scale, silt-sized particles are between 4.0 and 62.5 micrometres and clay is smaller than 4.0 micrometres. [1]
  • Particles with a nominal diameter of 2.0 millimetres and up are classed as gravel. [1]

How many fit?

  • ≈ 810–28,000 × Grain of sand · grain diameter (sand size class) lined up end to end match the Human · height
  • ≈ 1–29 × Human hair (width) · average diameter lined up end to end match the Grain of sand · grain diameter (sand size class)

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

  • 0.9–29× A grain of sand is roughly as wide as the width of a human hair: between 0.9 and 29 times as wide, depending on size. See side by side
  • 1/1.7–80 A black garden ant is about 1.7–80 times as long as a grain of sand is wide. See side by side
  • 1/3.3–120 A grain of rice is about 3.3–120 times as long as a grain of sand is wide. See side by side
  • 1/5–240 A honeybee is about 5–240 times as long as a grain of sand is wide. See side by side
  • 1/9.5–300 A US penny is about 9.5–300 times as wide as a grain of sand. See side by side
  • 1/810–28,000 An average adult is about 810–28,000 times as tall as a grain of sand is wide. See side by side

Factors compare the grain diameter (sand size class) of a grain of sand 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

  • Sand is a size class, so a single grain can be anywhere in the range; the limits follow Wentworth (1922).
  • Grain mass depends on size and mineral, so no single mass is given.

Sources

  1. U.S. Geological Survey, Surficial Sediment Data from the Gulf of Maine, Georges Bank, and Vicinity: A GIS Compilation (Open-File Report 03-001), Sediment nomenclature. Accessed 25 September 2026.

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