Physical quantity 
CGS.
unit 
FPS unit 
length, metre, meter (m) 
1 centimetre (cm) = 0.3937 inch (in)

1 inch (in) = 25.4 millimetre (mm)

" 
1 metre = 3.2808 feet (ft)

1 foot (ft) = 0.3048 metre (m)

"

1 metre (m) = 1.094 yard (yd)

1 yard (yd) = 0.9144 metre (m)

" 
1 kilometre (km) = 0.6213 mile

1 mile = 1.6093 kilometre (km) 
mass, kilogram (kg) 
1 gram (g) = 10^{3} kilogram (kg)
1 gram (g) = 0.0353 ounce (oz.)
1 kilogram (kg) = 2.205 pounds (lb) 
1 ounce (oz) = 28.35 gram (g)
1 pound (lb) = 0.4536 kilogram (kg)
.

"
"
"
"

1 tonne (t) = 1.102 US short ton, 2000 pounds (lb)
1 tonne (t) = 0.9843 US long ton, 2, 205 pounds (lb)
.
.

1 US hundredweight (cwt) = 100 pound (lb)
1 US cwt = 45.36 kilogram (kg)
1 US short ton = 0.9072 tonne (t)
1 US long ton = 1.016 tonne (t) 
volume, litre, liter (L)
1 cm^{3} = 10^{6} m^{3}
1 litre (L) =10^{3} m^{3}
1 millilitre (mL) = 1 cm^{3}

1 cubic centimetre (cc) = 0.0610 cubic inch
1 millilitre (mL) = 0.3382 fluid ounce
1 litre (L) = 0.2642 US liquid gallon
1 litre (L) = 0.02838 US bushel
.

1 cubic inch = 16.38 cubic centimetre (cc)
1 fluid ounce = 29.47 millilitre (mL)
1 US liquid gallon = 3.785 litre (L)
1 US bushel = 35.24 litre (L)
1 quart (liquid) = 0.9463 litre (L)

density
.

1 g cm^{3} = 10^{3} kg m^{3
}1 kilogramme / hectolitre = 0.7770 pound / US bushel 
1 pound / US bushel = 1.287 kg / hL
.

velocity or speed 
1 cm s^{1} = 10^{2} m s^{1} 
. 
" 
100 km / hour 
62.5 miles / hour 
force

dyne, 1 dyne = 10^{5} newton (N) 
.

pressure

1 dyne cm^{2} = 10^{1} pascal (Pa) 
. 
" 
1 bar = 10^{5} pascal (Pa) 
1 bar = 750.07 mm Hg 
" 
millibar = 100 pascal (Pa) 
. 
energy, work (J = joule) 
1 erg = 10^{7} joule (J)

.

power (W = watt)

1 erg S^{1} = 10^{7} watt (W) 
1 horsepower (hp) = 745.7 watt (W) 
viscosity

1 poise (P) = 10^{1 }NM^{2}s 
.

temperature
.

0^{o}C (Celsius) = 32^{o}F (Fahrenheit)
100^{o}C = 212^{o}F 
32^{o}F (Fahrenheit) = 0^{o}C (Celsius)
212^{o}F = 100^{o}C 
thermal energy

1 calorie (cal) = 4.186 joule (J) 
British thermal unit, 1 BTU = 1.055 × 10^{3} J 