Conversion Factors, Abbreviations, and Acronyms

Conversion Factors

Conversion Factors

English to Metric
Abbreviation From Multiply by To Abbreviation
in. inches 2.5 centimeters cm
ft feet 30 centimeters cm
ft feet 0.3048 meters m
yd yards 0.9 meters m
mi miles 1.609 kilometers km
in2 square inches 6.5 square centimeters cm2
ft2 square feet 0.0929 square meters m2
yd2 square yards 0.8 square meters m2
mi2 square miles 2.59 square kilometers km2
ac acres 4,047 square meters m2
ac acres 0.4 hectares ha
pt pints 0.47 liters L
qt quarts 0.95 liters L
gal gallons 3.8 liters L
gal/min gallons per minute 6.309 x 10-5 cubic meters per second m3/s
ft3 cubic feet 0.0283 cubic meters m3
yd3 cubic yards 0.76 cubic meters m3
cfs or ft3/s cubic feet per second 0.0283 cubic meters per second m3/s
cfs or ft3/s cubic feet per second 0.646 million gallons per day Mgal/d
Mgal/d million gallons per day 0.0438 cubic meters per second m3/s
Mgal/d million gallons per day 1.547 cubic feet per second cfs or ft3/s
F degrees Fahrenheit 5/9 (F)-32 degrees Celsius C
ppm parts per million 1 milligrams per liter mg/L

Metric to English
Abbreviation From Multiply by To Abbreviation
cm centimeters 0.4 inches in.
m meters 3.281 feet ft
m meters 1.1 yards yd
km kilometers 0.6214 miles mi
cm2 square centimeters 0.16 square inches in2
m2 square meters 10.76 square feet ft2
m2 square meters 1.2 square yards yd2
km2 square kilometers 0.3861 square miles mi2
m2 square meters 0.0002471 acres ac
ha hectares (10,000 m2) 2.5 acres ac
mL milliliters 0.03 fluid ounces fl oz
L liters 2.1 pints pt
L liters 1.06 quarts qt
L liters 0.26 gallons gal
m3 cubic meters 35.31 cubic feet ft3
m3 cubic meters 1.3 cubic yards yd3
m3/s cubic meters per second 35.31 cubic feet per second cfs or ft3/s
m3/s cubic meters per second 22.821 million gallons per day Mgal/d
C degrees Celsius 9/5 (C)+32) degrees Fahrenheit F
mg/L milligrams per liter 1 parts per million ppm


ft/s, foot per second
g, gram
gal/min, gallon per minute
g/L, gram per liter
in., inch
L/min, liter per minute
g/L, microgram per liter (equivalent to parts per billion)
m, micrometer
meq/L, milliequivalent per liter
mg/L, milligram per liter (equivalent to parts per million)
mL, milliliter
mm, millimeter
S/cm, microsiemens per centimeter
N, normality
ppb, parts per billion (equivalent to microgram per liter)
ppm, parts per million (equivalent to milligram per liter)


ADEQ, Arizona Department of Environmental Quality
ANC, acid-neutralizing capacity
ASTM, American Society for Testing and Materials
BOD, biochemical oxygen demand
BOR, U.S. Bureau of Reclamation
CFC, chlorofluorocarbon
CH/DH, clean hands/dirty hands
CNA, Comision Nacional del Agua
CPR, cardiopulmonary resuscitation
CRWQCB, California Regional Water Quality Control Board
DIW, deionized water
DO, dissolved oxygen
DOC, dissolved organic carbon
DPD, N,N-diethyl-p-phenylenediamine
DQO, data-quality objective
EDI, equal-discharge increment
EWI, equal-width increment
FAS, ferrous ammonium sulfate
FISP, Federal Interagency Sedimentation Project
GIS, geographic information system
GPS, global positioning system
IBWC, International Boundary and Water Commission
IPT, inflection point titration
ITFM, Intergovernmental Task Force for Water-Quality Monitoring
MF, membrane filtration
MPN, most probable number
MRL, minimum reporting level
MSDS, Material Safety Data Sheets
NGO, nongovernmental organizations
PAO, phenylarsineoxide
PCB, polychlorinated biphenyls
PFD, personal flotation device
PVC, polyvinyl chloride
QA/QC, quality assurance/quality control
SOC, suspended organic carbon
TNRCC, Texas Natural Resource Conservation Commission
TOC, total organic carbon
USEPA, U.S. Environmental Protection Agency
USGS, U.S. Geological Survey
VCF, vertical at centroid of flow
VOC, volatile organic compound
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