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Appendix B: Conversion Factors

Table B1 - Length

  m cm km
1 meter 1 102 10-3
1 centimeter 10-2 1 10-5
1 kilometer 103 105 1
1 inch 2.540 x 10-2 2.540 2.540 x 10-5
1 foot 0.3048 30.48 3.048 x 10-4
1 mile 1609 1.609 x 104 1.609
1 angstrom 10-10 10-8 10-13
1 fermi 10-15 10-13 10-18
1 light-year 9.460 x 1015 9.460 x 1017 9.460 x 1012

 

  in ft mi
1 meter 39.37 3.281 6.214 x 10−4
1 centimeter 0.3937 3.281 x 10−2 6.214 x 10−6
1 kilometer 3.937 x 104 3.281 x 10−4 0.6214
1 inch 1 8.333 x 10−2 1.578 x 10−5
1 foot 12 1 1.894 x 10−4
1 mile 6.336 x 104 5280 1

Area

1 cm2 = 0.155 in2

1 m2 = 104 cm2 = 10.76 ft2

1 in2 = 6.452 cm2

1 ft2 = 144 in2 = 0.0929 m2

Volume

1 liter = 1000 cm3 = 10−3 m3 = 0.03531 ft3 = 61.02 in3

1 ft3 = 0.02832 m3 = 28.32 liters = 7.477 gallons

1 gallon = 3.788 liters

Table B2 - Time

  s min h day yr
1 second 1 1.667 x 10-2 2.778 x 10-4 1.157 x 10-5 3.169 x 10-8 
1 minute 60 1 1.667 x 10-2 6.944 x 10-4 1.901 x 10-6
1 hour 3600 60 1 4.167 x 10-2 1.141 x 10-4
1 day 8.640 x 104 1440 24 1 2.738 x 10-3
1 year 3.156 x 107 5.259 x 105 8.766 x 103 365.25 1

Table B3 - Speed

  m/s cm/s ft/s mi/h
1 meter/second 1 102 3.281 2.237
1 centimeter/second 10-2 1 3.281 x 10−2 2.237 x 10−2
1 foot/second 0.3048 30.48 1 0.6818
1 mile/hour 0.4470 44.70 1.467 1

Acceleration

1 m/s2 = 100 cm/s2 = 3.281 ft/s2

1 cm/s2 = 0.01 m/s2 = 0.03281 ft/s2

1 ft/s2 = 0.3048 m/s2 = 30.48 cm/s2

1 mi/h • s = 1.467 ft/s2

Table B4 - Mass

  kg g slug u
1 kilogram 1 103 6.852 x 10-2 6.024 x 1026
1 gram 10-3 1 6.852 x 10-5 6.024 x 1023
1 slug 14.59 1.459 x 104 1 8.789 x 1027
1 atomic mass unit 1.661 x 10-27 1.661 x 10-24 1.138 x 10-28 1
1 metric ton 1000      

Table B5 - Force

  N dyne lb
1 newton 1 105 0.2248
1 dyne 10-5 1 2.248 x 10-6
1 pound 4.448 4.448 x 105 1

Table B6 - Pressure

*Where the acceleration due to gravity is 9.80665 m/s2 and the temperature is 0 °C

  Pa dyne/cm2 atm cm Hg lb/in2
1 pascal 1 10 9.869 x 10−6 7.501 x 10−4 1.450 x 10−4
1 dyne/ centimeter2 0.1 1 9.869 x 10−7 7.501 x 10−5 1.450 x 10−5
1 atmosphere 1.013 x 105 1.013 x 106 1 76 14.70
1 centimeter mercury* 1.333 x 103 1.333 x 104 1.316 x 10-2 1 0.1934
1 pound/inch2 6.895 x 103 6.895 x 104 6.805 x 10-2 5.171 1
1 bar 105        
1 torr       1 (mm Hg)  

Table B7 - Work, Energy, Heat

  J erg ft • lb eV cal Btu
1 joule 1 107 0.7376 6.242 x 1018 0.2389 9.481 x 10-4
1 erg 10-7 1 7.376 x 10-8 6.242 x 1011 2.389x 10-8 9.481 x 10-11
1 foot-pound 1.356 1.356 x 107 1 8.464 x 1018 0.3239 1.285 x 10-3
1 electron-volt 1.602 x 10-19 1.602 x 10-12 1.182 x 10-19 1 3.827 x 10-20 1.519 x 10-22
1 calorie 4.186 4.186 x 107 3.088 2.613 x 1019 1 3.968 x 10-3
1 British thermal unit 1.055 x 103 1.055 x 1010 7.779 x 102 6.585 x 1021 2.520 x 102 1
1 kilowatt-hour 3.600 x 106          

Power

1 W = 1 J/s

1 hp = 746 W = 550 ft • lb/s

1 Btu/h = 0.293 W

Angle

1 rad = 57.30° = \(\frac{180^{o}}{\pi}\)

1° = 0.01745 rad = \(\frac{\pi}{180\; rad}\)

1 revolution = 360° = 2\(\pi\) rad

1 rev/min (rpm) = 0.1047 rad/s

Contributors

  • Samuel J. Ling (Truman State University), Jeff Sanny (Loyola Marymount University), and Bill Moebs with many contributing authors. This work is licensed by OpenStax University Physics under a Creative Commons Attribution License (by 4.0).