Units of the The International System of Units
(Syst?me international d'unités, SI)
and unit coversion


SI base units:

Quantity name Unit name Symbol
Length meter m
Mass kilogram kg
Time second s
Electric current ampere A
Force netwon N
Torque newton-metre Nm
Power watt W
Energy joule J
Pressure pascal Pa
Temperature kelvin K

Standard prefixes:

tera T 1000 000 000 000 = 1012 1 TW = 1000 000 000 000 W
giga G 1000 000 000 = 109 1 GW = 1000 000 000 W
mega M 1000 000 = 106 1 MW = 1000 000 W
kilo k 1000 = 103 1 kW = 1000 W
hecto h 100 = 102 1 hl = 100 l
deca da 10 1 daN = 10 N
deci d 0,1 =10-1 1 dm = 0,1 m
centi c 0,01=10-2 1 cm = 0,01 m
milli m 0,001=10-3 1 mm = 0,001 m
micro ? 0,000 001=10-6 1 ?m = 0,000 001 m
nano n 0,000 000 001=10-9 1 nm = 0,000 000 001 m
pico p 0,000 000 000 001=10-12 1 pm = 0,000 000 000 001 m
femto f 0,000 000 000 000 001=10-15 1 fm = 0,000 000 000 000 001 m
atto a 0,000 000 000 000 000 001=10-18 1 am = 0,000 000 000 000 000 001 m

 


Non-SI units accepted for use with SI:

Quantity name Unit name Symbol Equivalent SI unit
Volume litre l 1 l = 1 dm3 = 0,001 m3
Mass tonne t 1 t = 1 Mg = 1000 kg
Pressure bar bar 1 bar = 105 Pa
Area are a 1 a = 102 m2
Plane angle angle o 1o = 17,45 mrad
minute ' 1' = 1o/60 = 0,291 mrad
second '' 1'' = 1'/60 = 4,85 rad
Time minute min 1 min = 60 s
hour h 1 h = 3600 s
Speed kilometer per hour km/h

1 km/h = 1/3,6m/s

1 m/s = 3,6 km/h

 


Units derived from SI base units and their conversion:

1N = 0,102 kG* (kilogram force) 1 kG = 9,81 N
 
1 Nm = 0,102 kGm (= 1 J (joule)) 1 kGm = 9,81 Nm
 
1 W = 0,102 kGm/s (= 1 J/s) 1 kGm/s = 9,81 W
1 kW = 1,36 KM 1 KM = 0,736 kW
1 kW =860 kcal/h 1 kcal/h = 0,00116 kW
 
1 J = 0,102 kGm 1 kGm = 9,81 J
1 J = 0,239 cal 1 cal = 4,19 J
 
1 ar = 100 m2 1 m2 =0,01 ar
1 ha = 10 000 m2 1 ha = 100 ar
 
1 Pa = (1 N/m2) = 0,102 kG/m2 1 kG/m2 = 9,81 Pa = 9,81 N/m2
 
T(Fahrenheit) = 32 + 9/5*T(Celsius) T(Celsius) = 5/9*[T(Fahrenheit) - 32]
20oC = 68 fahrenheit [st. F]
T(Kelvin) = 273 + T(Celsius) T(Celsius) = T(Kelvin) - 273
 
1 land mile = 1609,34 m 1 m = 0,00062 land mile
1 yard = 0,9 m 1 m = 1,09 yard
1 foot = 0,3048 m 1 m = 3,28 feet
1 inch = 25,4 mm = 0,0254 m 1 m = 39,37 inches
 
1 quintal = 100 kg 1 kg = 0,01 quintal
1 pound = 0,4536 kg 1 kg = 2,2 pounds
1 ounce = 0,0286 kg 1 kg = 35,27 ounces
 
1 gallon = 4,5459 litre [l] 1 litr [l] = 0,22 gallon
1 barrel =163,66 litre [l] 1 litre [l] = 0,0061 barrel



In practice one can assume that:

1 kG = 10 N

1 N = 0,1 kG

Force unit is newton (N) (old unit of the force - 1 kG = 9,81 N), unit of mass is kilogram (kg), the difference results from the acceleration of gravity 9,81 m/s2.