Page 16 - Handbook of Civil Engineering Calculations, Second Edition

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TABLE 1. Commonly Used USCS and SI Units* (Continued)

SI Conversion factor—multiply USCS unit by this factor
USCS unit SI unit symbol to obtain the SI unit
square yard square meter m 2 0.08361

cubic yard cubic meter m 3 0.076455
acre feet cubic meter m 3 1233.49

acre square meter m 2 4046.87
3
cubic foot per cubic meter per m /s 0.0004719
minute second
*Because of space limitations this table is abbreviated. For a typical engineering practice an actual table would be many
times this length.

TABLE 2. Typical Conversion Table*

To convert from To Multiply by

square feet square meters 9.290304 E 02
foot per second squared meter per second squared 3.048 E 01
cubic feet cubic meters 2.831685 E 02
pound per cubic inch kilogram per cubic meter 2.767990 E + 04

gallon per minute liters 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
Note: 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 feet 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 convert pounds per cubic
3
3
3
inch to kilograms per cubic meter, find 1 lb = 0.4535924 kg, and 1 in = 0.00001638706 m . Then, 1 lb/in = 0.4535924
3
kg/0.00001638706 m 27,680.01, or 2.768 E + 4.
*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.