## Conversion Factors

Length
m cm km
1 meter 1 102 10−3
1 centimeter 10−2 1 10−5
1 kilometer 103 105 1
1 inch $2.540\,×\,{10}^{-2}$ 2.540 $2.540\,×\,{10}^{-5}$
1 foot 0.3048 30.48 $3.048\,×\,{10}^{-4}$
1 mile 1609 $1.609\,×\,{10}^{4}$ 1.609
1 angstrom 10−10
1 fermi 10−15
1 light-year $9.460\,×\,{10}^{12}$
in. ft mi
1 meter 39.37 3.281 $6.214\,×\,{10}^{-4}$
1 centimeter 0.3937 $3.281\,×\,{10}^{-2}$ $6.214\,×\,{10}^{-6}$
1 kilometer $3.937\,×\,{10}^{4}$ $3.281\,×\,{10}^{3}$ 0.6214
1 inch 1 $8.333\,×\,{10}^{-2}$ $1.578\,×\,{10}^{-5}$
1 foot 12 1 $1.894\,×\,{10}^{-4}$
1 mile $6.336\,×\,{10}^{4}$ 5280 1

Area

$1\,{\text{cm}}^{2}=0.155\,{\text{in.}}^{2}$

$1\,{\text{m}}^{2}={10}^{4}\,{\text{cm}}^{2}=10.76\,{\text{ft}}^{2}$

$1\,{\text{in.}}^{2}=6.452\,{\text{cm}}^{2}$

$1\,{\text{ft}}^{2}=144\,{\text{in.}}^{2}=0.0929\,{\text{m}}^{2}$

Volume

$1\,\text{liter}=1000\,{\text{cm}}^{3}={10}^{-3}\,{\text{m}}^{3}=0.03531\,{\text{ft}}^{3}=61.02\,{\text{in.}}^{3}$

$1\,{\text{ft}}^{3}=0.02832\,{\text{m}}^{3}=28.32\,\text{liters}=7.477\,\text{gallons}$

$1\,\text{gallon}=3.788\,\text{liters}$

Time
s min h day yr
1 second 1 $1.667\,×\,{10}^{-2}$ $2.778\,×\,{10}^{-4}$ $1.157\,×\,{10}^{-5}$ $3.169\,×\,{10}^{-8}$
1 minute 60 1 $1.667\,×\,{10}^{-2}$ $6.944\,×\,{10}^{-4}$ $1.901\,×\,{10}^{-6}$
1 hour 3600 60 1 $4.167\,×\,{10}^{-2}$ $1.141\,×\,{10}^{-4}$
1 day $8.640\,×\,{10}^{4}$ 1440 24 1 $2.738\,×\,{10}^{-3}$
1 year $3.156\,×\,{10}^{7}$ $5.259\,×\,{10}^{5}$ $8.766\,×\,{10}^{3}$ 365.25 1
Speed
m/s cm/s ft/s mi/h
1 meter/second 1 102 3.281 2.237
1 centimeter/second 10−2 1 $3.281\,×\,{10}^{-2}$ $2.237\,×\,{10}^{-2}$
1 foot/second 0.3048 30.48 1 0.6818
1 mile/hour 0.4470 44.70 1.467 1

Acceleration

$1\,{\text{m/s}}^{2}=100\,{\text{cm/s}}^{2}=3.281\,{\text{ft/s}}^{2}$

$1\,{\text{cm/s}}^{2}=0.01\,{\text{m/s}}^{2}=0.03281\,{\text{ft/s}}^{2}$

$1\,{\text{ft/s}}^{2}=0.3048\,{\text{m/s}}^{2}=30.48\,{\text{cm/s}}^{2}$

$1\,\text{mi/h}·\text{s}=1.467\,{\text{ft/s}}^{2}$

Mass
kg g slug u
1 kilogram 1 103 $6.852\,×\,{10}^{-2}$ $6.024\,×\,{10}^{26}$
1 gram 10−3 1 $6.852\,×\,{10}^{-5}$ $6.024\,×\,{10}^{23}$
1 slug 14.59 $1.459\,×\,{10}^{4}$ 1 $8.789\,×\,{10}^{27}$
1 atomic mass unit $1.661\,×\,{10}^{-27}$ $1.661\,×\,{10}^{-24}$ $1.138\,×\,{10}^{-28}$ 1
1 metric ton 1000
Force
N dyne lb
$1$ newton 1 105 0.2248
$1$ dyne 10−5 1 $2.248\,×\,{10}^{-6}$
$1$ pound 4.448 $4.448\,×\,{10}^{5}$ 1
Pressure
Pa dyne/cm2 atm cmHg lb/in.2
*Where the acceleration due to gravity is $9.80665\,{\text{m/s}}^{2}$ and the temperature is $0\text{°}\text{C}$
1 pascal 1 10 $9.869\,×\,{10}^{-6}$ $7.501\,×\,{10}^{-4}$ $1.450\,×\,{10}^{-4}$
1 dyne/centimeter2 10−1 1 $9.869\,×\,{10}^{-7}$ $7.501\,×\,{10}^{-5}$ $1.450\,×\,{10}^{-5}$
1 atmosphere $1.013\,×\,{10}^{5}$ $1.013\,×\,{10}^{6}$ 1 76 14.70
1 centimeter mercury* $1.333\,×\,{10}^{3}$ $1.333\,×\,{10}^{4}$ $1.316\,×\,{10}^{-2}$ 1 0.1934
1 pound/inch2 $6.895\,×\,{10}^{3}$ $6.895\,×\,{10}^{4}$ $6.805\,×\,{10}^{-2}$ 5.171 1
1 bar 105
1 torr 1 (mmHg)
Work, Energy, Heat
J erg ft.lb
1 joule 1 107 0.7376
1 erg 10−7 1 $7.376\,×\,{10}^{-8}$
1 foot-pound 1.356 $1.356\,×\,{10}^{7}$ 1
1 electron-volt $1.602\,×\,{10}^{-19}$ $1.602\,×\,{10}^{\text{-12}}$ $1.182\,×\,{10}^{-19}$
1 calorie 4.186 $4.186\,×\,{10}^{7}$ 3.088
1 British thermal unit $1.055\,×\,{10}^{3}$ $1.055\,×\,{10}^{10}$ $7.779\,×\,{10}^{2}$
1 kilowatt-hour $3.600\,×\,{10}^{6}$
eV cal Btu
1 joule $6.242\,×\,{10}^{18}$ 0.2389 $9.481\,×\,{10}^{-4}$
1 erg $6.242\,×\,{10}^{11}$ $2.389\,×\,{10}^{-8}$ $9.481\,×\,{10}^{-11}$
1 foot-pound $8.464\,×\,{10}^{18}$ 0.3239 $1.285\,×\,{10}^{-3}$
1 electron-volt 1 $3.827\,×\,{10}^{-20}$ $1.519\,×\,{10}^{-22}$
1 calorie $2.613\,×\,{10}^{19}$ 1 $3.968\,×\,{10}^{-3}$
1 British thermal unit $6.585\,×\,{10}^{21}$ $2.520\,×\,{10}^{2}$ 1

Power

$1\,\text{W}=1\,\text{J/s}$

$1\,\text{hp}=746\,\text{W}=550\,\text{ft}·\text{lb/s}$

$1\,\text{Btu/h}=0.293\,\text{W}$

Angle

$1\,\text{rad}=57.30\text{°}=180\text{°}\text{/}\text{π}$

$1\text{°}=0.01745\,\text{rad}=\text{π}\text{/}180\,\text{rad}$

$1\,\text{revolution}=360\text{°}=2\text{π}\,\text{rad}$

$1\,\text{rev/min}(\text{rpm})=0.1047\,\text{rad/s}$