USGS Data Series 423

## Selected Physical, Chemical, and Biological Data Used to Study Urbanizing Streams in Nine Metropolitan Areas of the United States, 1999–2004

National Water-Quality Assessment Program

# Conversion Factors

Multiply By To obtain
Length
centimeter (cm) 0.3937 inch (in.)
millimeter (mm) 0.03937 inch (in.)
micron (µm) 0.0003937 inch (in.)
meter (m) 3.281 foot (ft)
kilometer (km) 0.6214 mile (mi)
Area
square meter (m2) 0.0002471 acre
hectare (ha) 2.471 acre
square kilometer (km2) 247.1 acre
square centimeter (cm2) 0.001076 square foot (ft2)
square meter (m2) 10.76 square foot (ft2)
square centimeter (cm2) 0.1550 square inch (ft2)
hectare (ha) 0.003861 square mile (mi2)
square kilometer (km2) 0.3861 square mile (mi2)
Volume
liter (L) 33.82 ounce, fluid (fl. oz)
liter (L) 2.113 pint (pt)
liter (L) 1.057 quart (qt)
liter (L) 0.2642 gallon (gal)
cubic meter (m3) 264.2 gallon (gal)
cubic meter (m3) 0.0002642 million gallons (Mgal)
liter (L) 61.02 cubic inch (in3)
cubic meter (m3) 35.31 cubic foot (ft3)
cubic meter (m3) 1.308 cubic yard (yd3)
cubic meter (m3) 0.0008107 acre-foot (acre-ft)
Flow rate
meter per second (m/s) 3.281 foot per second (ft/s)
cubic meter per second (m3/s) 70.07 acre-foot per day (acre-ft/d)
cubic meter per second (m3/s) 35.31 cubic foot per second (ft3/s)
cubic meter per second (m3/s) 22.83 million gallons per day (Mgal/d)
Mass
gram (g) 0.03527 ounce, avoirdupois (oz)

SI Prefixes:

milli = 10-3

micro = 10-6

nano = 10-9

pico = 10-12

micron = micrometer

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

°F = (1.8 × °C) + 32

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

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

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (µS/cm at 25 °C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) or micrograms per liter (µg/L).

U.S. Department of the Interior | U.S. Geological Survey
URL: https://pubs.usgs.gov/ds/423/units.html