Table C-4. Conversion factors: English to metric (SI) units of measurement 



The following conversion factors adopted by the U.S. Department of Defense are those published by ttie American Society for Testlnjj and 

 Materials (ASTM) (Standard for Metric Practice, December 1979), except that additional uerlved conversion factors have been added. The metric 

 units and conversion factors adopted by ASTM are based on the "International System of Units" (designated SI) which has been fixed by the 

 International Committee for Weights and Measures. 



For most scientific and technical work It is generally accepted that the metric SI system of units Is superior to all other systems of 

 units. The SI Is the most widely accepted and used language for scientific and technical data and specifications. 



In the SI system the unit of mass is the kJ,logram (kg) and the unit of force is the newton (N). N is defined as tlie force whicli, when 

 applied to a mass of 1 kg, gives the mass an acceleration of 1 m/s . 



Former metric systems used kilogram-force as the force unit , and this has resulted in the conversion of pound-force to kllo^ram-torce In 

 many present-day situations, particularly in expressing the weight of a body. In the SI system the weight of a body Is correctly ex^jressed m 

 newtons . Uhen the value for weight Is encountered expressed in kilograms, it Is best to first convert It Into newtons by multiplying kilograms 

 by 9.80665 This provides consistent usage of the SI system, and will help to eliminate errors in derived units. 



Multiply 



Length 



Inches 

 feet . 



2.34 . 

 0.304 8 



yards 



fathoms 



statute miles (U.S.) 



centimeters 

 meters 



nautical miles 1 852.0 



. 0.914 4^ meters 



. 1.828 8 meters 



1 609.4 meters 



. 1.609 34 kilometers 



1 



1.852 



meters 

 kilometers 



Area 



square Inches 6.4516 square centimeters 



square feet 0.092 903 . . . . square meters 



square yards 0.836 127 square meters 



acres 0.404 687 hectares 



4 046.87 square meters 



square miles (U.S. statute) 2.589 99 square kilometers 



Volume 



cubic Inches .... 



cubic feet 



cubic yards 



cubic yards per foot 



16.387 I cubic centimeters 



. 0.028 316 8 . . . . cubic meters 



0.764 555 cubic meters 



. 2.508 38 cubic meters per meter 



Liquid Capacity 



fluid ounces (U.S.) 



liquid pints (U.S.) 

 quarts (U.S.) . . . 

 gallons (U.S.) . . . 



cubic feet 



acre-feet 



29.573 5 cubic centimeters 



. 29.573 5 milliliters 



. . 0.473 176 liters 



. . 0.946 353 liters 



. . 3.785 41 liters 



. 28.316 8 liters 



1 233.48 cubic meters 



Mass 



ounces (avoirdupois) 



pounds (avoirdupois) 



slugs U.593 902 9 



28.349 5 grams 



0.453 592 37^ 

 1 



kilograms 

 kilograms 



ounces per cubic Inch 



pounds per cubic foot 

 slugs per cubic foot . 



I 729.99 kilograms per cubic meter 



16.0185 kilograms per cubic meter 



. 515.379 kilograms per cubic meter 



Force (Weight) 



pounds-force 4.448 22 newtons 



kips (1000 Ibf) 4.448 22 kilonewtons 



kilograms-force 9.806 65 newtons 



short tons (2000 Ibf) 8.896 44 kilonewtons 



long tons (2240 Ibf) 9.964 02 kilonewtons 



Exact conversion value. 



^Technically, maas-to-f orce conversion. 



C-36 



