Page 21 - Civil Engineering Formulas

2 CHAPTER ONE

TABLE 1.1 Commonly Used USCS and SI Units*
Conversion factor
(multiply USCS unit
by this factor to
USCS unit SI unit SI symbol obtain SI unit)
Square foot Square meter m 2 0.0929
Cubic foot Cubic meter m 3 0.2831
Pound per Kilopascal kPa 6.894
square inch
Pound force Newton N 4.448
Foot pound Newton meter N m 1.356
torque
Kip foot Kilonewton meter kN m 1.355
Gallon per Liter per second L/s 0.06309
minute
Kip per square Megapascal MPa 6.89
inch

*This table is abbreviated. For a typical engineering practice, an actual table would be
many times this length.

TABLE 1.2 Typical Conversion Table*

To convert from To Multiply by †
Square foot Square meter 9.290304 E 02
Foot per second Meter per second
squared squared 3.048 E 01
Cubic foot Cubic meter 2.831685 E 02
Pound per cubic inch Kilogram per cubic meter 2.767990 E 04
Gallon per minute Liter per second 6.309 E 02
Pound per square inch Kilopascal 6.894757
Pound force Newton 4.448222
Kip per square foot Pascal 4.788026 E 04
Acre foot per day Cubic meter per second 1.427641 E 02
Acre Square meter 4.046873 E 03
Cubic foot per second Cubic meter per second 2.831685 E 02
*This table contains only selected values. See the U.S. Department of the Interior Metric Manual,
or National Bureau of Standards, The International System of Units (SI), both available from the U.S.
Government Printing Office (GPO), for far more comprehensive listings of conversion factors.
† The E indicates an exponent, as in scientific notation, followed by a positive or negative number,
representing the power of 10 by which the given conversion factor is to be multiplied before use. Thus,
for the square foot conversion factor, 9.290304 1/100 0.09290304, the factor to be used to convert
square feet to square meters. For a positive exponent, as in converting acres to square meters, multiply
by 4.046873 1000 4046.8.
Where a conversion factor cannot be found, simply use the dimensional substitution. Thus, to con-
3
vert pounds per cubic inch to kilograms per cubic meter, find 1 lb 0.4535924 kg and 1 in
3
3
3
0.00001638706 m . Then, 1 lb/in 0.4535924 kg/0.00001638706 m 27,680.01, or 2.768 E 4.