Many geoprocessing tools, including Spatial Join, Densify, and Generate Points Along Lines, have a parameter for specifying a linear distance and units. Several other tools, including Simplify Building and Subdivide Polygon, have a parameter for specifying an areal distance and units. These parameter types are commonly used for setting spatial tolerances and for applying a linear or areal interval at which some spatial action is undertaken.
In the Geoprocessing pane, both the Linear Unit and Area Unit parameters are displayed as a text box for a numeric value and a choice list of valid unit types. In Python, both parameter types are expressed as a string as a distance value and unit types, for example, "3.5 Kilometers".
The tables below provide information about the units of measurement used in geoprocessing tools. Each row provides the unit name found in tools in the Geoprocessing pane and its corresponding keyword for use in Python as well as a description.
The following units are available for the measurement of length:
Metric base unit of distance.
0.1 of a meter.
0.01 of a meter.
0.001 of a meter.
International Nautical Miles
0.3048 meters. Required for new coordinate systems used by U.S. government agencies beginning in 2023.
US Survey Nautical Miles
US Survey Miles
US Survey Yards
US Survey Feet
1,200/3937 meters or 0.3048006096012192. Used in existing U.S. coordinate systems based on NAD27 and NAD83. Usage will be phased out starting in 2023.
US Survey Inches
Angular unit of measure based on 1/360 of a circle. The actual length of a degree depends on its location on the spherical or ellipsoidal model that is being used.
The following units are available for the measurement of area:
Area of a square 1 kilometer per side
Standard metric unit of land area as defined by a square 100 meters per side
Area of a square 10 meters per side
Area of a square 1 meter per side
Area of a square 1 decimeter per side
Area of a square 1 centimeter per side
Area of a square 1 millimeter per side
Square Statute Miles
Area of a square 1 Statue mile per side
Area of 4046.8564224 square meters
Square International Yards
Area of a square 1 international yard per side
Square International Feet
Area of a square 1 international foot per side
Square International Inches
Area of a square 1 international inch per side
Square US Survey Miles
Area of a square 1 US Survey mile per side.
US Survey Acres
Used when working with US Survey feet and equal to 43,560 square U.S. Survey Feet or 4,046.872 square meters
Square US Survey Yards
Area of a square 1 US Survey yard per side
Square US Survey Feet
Area of a square 1 US Survey foot per side
Square US Survey Inches
Area of a square 1 US Survey inch per side