Grain of sand (Medium)
0.375 mm
Grain diameter
A grain of medium sand, as geologists grade it. 0.25 to 0.5 mm across.
Published
How big is that?
0.375 mm is 5.4 times the width of a human hair and 5.2% of a grain of rice.
Grain of sand is the 13th smallest of the 32 Tiny Worlds objects, and the 13th smallest of the 172 objects across all five SizeItUp games.
Size comparison
To scale, smallest to largest: Grain of sand in orange beside the Tiny Worlds objects nearest in size, in teal.
| Object | Size | vs Grain of sand |
|---|---|---|
| Paramecium (P. caudatum)A slipper-shaped single cell that swims with thousands of tiny hairs. | 0.225 mm long | 60% of the size |
| Tardigrade (Water bear)A chubby eight-legged micro-animal that can survive drying out, seen from the side. | 0.25 mm long | 67% of the size |
| Grain of sand (Medium) | 0.375 mm across | – |
| Spider mite (Two-spotted, female)A sap-sucking mite that spins fine webs on houseplants, seen from above. | 0.4 mm long | 1.1× bigger |
| Amoeba (Amoeba proteus)A single cell that moves by pushing out pseudopods; big enough to see by eye. | 0.5 mm long | 1.3× bigger |
In other units
| Micrometres | 375 |
|---|---|
| Millimetres | 0.375 |
| Centimetres | 0.0375 |
| Metres | 0.000375 |
How it's measured
Grain diameter. Midpoint of the medium sand class, 0.25 to 0.5 mm (USGS, Udden-Wentworth scale).
The source gives a range, so this is the middle of it.
Sources
- apps.usgs.gov: USGS Thesaurus, medium sand: median grain size of 0.25 millimeters to < 0.5 millimeters.
Checked against the source on .
Could you have guessed it by eye?
Grain of sand is one of the objects in Tiny Worlds, a daily size comparison game: you stretch a shape to the size you think is right beside one you know.