Soil Classification

Classification by USDA (United State Department of Agriculture) :-

Soil Separates	Diameter (mm)
Clay	<0.002
Silt	0.002 – 0.05
Very fine sand	0.05 – 0.10
Fine sand	0.10 – 0.25
Medium sand	0.25 – 0.50
Coarse sand	0.50 – 1.00
Very Coarse sand	1.00 – 2.00

Classification by ISSS (Indian Socity of Soil Science) :-

Soil Separates	Diameter (mm)
Clay	<0.002
Silt	0.002 – 0.02
Fine sand	0.02 – 0.2
Coarse sand	0.2 – 2.0

According to the International System of Soil Classification size of different particle are as follows :-

Soil	Size (mm)
Clay	Less than 0.002
Silt	0.002 – 0.02
Sand	0.02 – 2.0
Gravel	Greater than 2.0