Guide for the Use of the International System of Units (SI)

Guide for the Use of the International System of Units (SI) 
 
56 
To convert from
 to
Multiply by 
watt per square inch (W / in
2
) .............................. watt per square meter (W / m
2
) ............ 1.550 003 E+03 
watt second (W · s) .............................................. joule (J) ........................................................... 1.0 E+00 
yard (yd) .............................................................. meter (m) .................................................... 9.144 E−01 
year (365 days) .................................................... second (s) .................................................. 3.1536 E+07 
year (sidereal) ...................................................... second (s) ............................................. 3.155 815 E+07 
year (tropical) ...................................................... second (s) ............................................. 3.155 693 E+07 

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Guide for the Use of the International System of Units (SI) 
 
57 
B.9 Factors for units listed by kind of quantity or field of science 
Caution: The units listed in column 1 are in general not to be used in NIST publications, with the exception 
of those few in italic type. 
Factors in boldface are exact 
To convert from
 to
 
Multiply by 
 
ACCELERATION 
acceleration of free fall, standard (g
n
) .................. meter per second squared (m / s
2
) .......... 9.806 65 E+00 
foot per second squared (ft / s
2
) ........................... meter per second squared (m / s
2
) ............... 3.048 E−01 
gal (Gal)................................................................ meter per second squared (m / s
2
) ................... 1.0 E−02 
inch per second squared (in / s
2
) .......................... meter per second squared (m / s
2
) ................. 2.54 E−02