Conversion Factors and Datums


Conversion Factors


Inch/Pound to SI


Multiply	By	To obtain
Length
inch (in.)	2.54	centimeter (cm)
inch (in.)	25.4	millimeter (mm)
foot (ft)	0.3048	meter (m)
mile (mi)	1.609	kilometer (km)
Area
acre	0.4047	hectare (ha)
square mile (mi2)	2.590	square kilometer (km2)
Volume
cubic foot (ft3)	0.02832	cubic meter (m3)
acre-foot (acre-ft)	1,233	cubic meter (m3)
Flow rate
cubic foot per second (ft3/s)	0.02832	cubic meter per second (m3/s)
foot per day (ft/d)	0.3048	meter per day (m/d)
Transmissivity*
foot squared per day (ft2/d)	0.09290	meter squared per day (m2/d)

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:


°C=(°F-32)/1.8.


*Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times foot of aquifer thickness [(ft³/d)/ft²]ft. In this report, the mathematically reduced form, foot squared per day (ft²/d), is used for convenience.


Datums


Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29).


Horizontal coordinate information is referenced to the North American Datum of 1927 (NAD 27).


Elevation, as used in this report, refers to distance above the vertical datum.


First posted April 23, 2014