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

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

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

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

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