| LENGTH |
m |
meter |
|
| km, (cm), mm, µm, nm |
1 inch = 25.4 mm
1 foot = 305 mm |
1 yard = 0.915 m
1 mile = 1.609 km |
 |
|
| MASS |
kg |
kilogram |
|
ton ( = 1000 kg)
g (gram) |
1 ounce = 28.35 g
1 pound = 454 g |
1 kip = 454 kg
1 tom = 1016 kg |
|
|
| TIME |
s |
second |
|
| ms (millisecond), minute, hour |
|
|
|
|
| TEMPERATURE |
°K |
degree kelvin |
|
1 degC (celsius) = 1 degK
N°C = N + 273.15°K |
1 degF = 5/9 degC
N°F = 5/9(N- 32)°C |
|
|
|
|
| LUMINOUS INTENSITY |
cd |
candela |
|
|
|
PREFIXES
TO UNITS - Multiples and Submultiples
| Fraction |
Name |
Abbreviation |
Multiple |
Name |
Abbreviation |
(10-¹
(10-²
(10-³
(10-6
(10-9
(10-12 |
deci
centi
milli
micro
nano
pico |
d)
c)
m
µ
n
p |
(10
(10²
(10³
(106
(109
(1012 |
deca
hecto
kilo
mega
giga
tera |
da)
h)
k
M
G
T |
|
|
| DERIVED UNITS |
| AREA |
m² |
meter squared |
|
| square with sides of unit length |
|
|
1 mm² = 10-6 m²
1 ha (hectare) = 104 m²
1 km² = 106 m² |
1 ft² = 0.093 m²
1 acre = 0.405 ha
1 mile² = 2.59 km² |
|
|
|
|
| VOLUME |
m³ |
cubic meter |
|
| cube with sides of unit length |
|
|
1 litre = 10 dm³ = 10-³ m³
1 cm³ = 10-6 m³ |
1 ft³ = 0.028 m³
1 gallon = 4.5461 |
|
|
|
|
| DENSITY |
kg/m³ |
kilogram per cubic meter |
| unit mass per unit volume |
1 lb/ft³ = 16.019 kg/m³ |
|
| 1 g/cm³ = 1000 kg/m³ |
1 lb/in³ = 27.68 g/cm³ |
|
|
|
| SURFACE DENSITY |
kg/m² |
kilogram per meter |
| unit mass per unit area |
1 lb/ft² = 4.882 kg/m² |
squared |
|
|
|
| VELOCITY (LINEAR) |
m/s |
meter per second |
| unit length movement in unit time |
|
|
| 1 km/h = 0.278 m/s |
1 ft/min = 0.005 m/s
1 ft/s = .305 m/s |
1 mph = 1.609 km/h
1 knot = 1.853 km/h |
|
|
| ACCELERATION
(LINEAR) m³ |
meter per second squared |
| unit velocity change in unit time |
1 ft/s² = 0.305 m/s² |
|
|
| FORCE |
N |
newton |
kg m/s² |
| causing unit acceleration of unit
mass |
|
|
| kN, MN |
1kbf = 4.448 N
1 kgf = 9.807 N |
1 dyn = 10-5 N |
|
|
|
| WORK, ENERGY |
J (N m) |
joule |
kg m²/s² |
| unit force acting over unit
length |
|
|
1 Wh= 3600 J
1 kWh = 3600 kJ |
1 erg = 0.1 µJ
1 cal = 4.187 J
1 kcal = 4187 J
1 m kgf = 9.807 J |
1 Btu = 1055.06 J
1 therm = 105.506 MJ
1 hp-h = 2684.5 kJ
1 ft lbf = 1.3556 J |
|
|
| POWER or ENERGY FLOW
RATE |
W (J/s) |
watt |
kg m²/s² |
| unit energy spent in unit time |
|
|
|
megawatt
kilowatt |
1 erg/s = 0.1 µW
1 cal/s = 4.187 W
1 kcal/h = 1.163 W
1 hp (metric) = 735.5 W |
1 Btu/h = 0.293 W
1 ton refrig = 3.516 kW
1 ft lbf/s = 1.356 W
1 hp = 745.7 W |
|
|
| DENSITY OF ENERGY
FLOW RATE (INTENSITY) |
W/m² |
watt per meter squared |
kg m²/s² |
| unit energy flow rate through
unit area |
|
|
kW/m², µW/m²
MJ/m².day |
1 Btu/ft²h = 3.155 W/m² |
1 kcal/m²h = 1.163 W/m² |
| 1 cal/cm²h = 1langley/h = 41.87
kJ/m² = 11.63 W/m² |
|
|
| PRESSURE, STRESS |
N/m² (pascal) |
newton per meter squared |
kg/m s² |
| unit force acting on unit area |
|
|
|
kN/m², MN/m²
1 bar = 100 kN/m²
1 m bar = 100 N/m² |
1 kgf/cm² = 98 kN/m²
1 kgf/m² = 9.8 kN/m²
1 atmosphere = 101.32 kN/m²
1 m water guage = 9.8 kN/m² |
1 lbf/in² = 6895 N/m²
1 lbf/ft² = 47.88 N/m²
1 tonf/ft² = 1.356 W
1 ft water guage = 2.99 N/m² |
|
|
| THERMAL CAPACITY |
J/degC |
|
|
| energy required by body for unit
temperature increase |
|
| 1 Btu/degF = 4.187 J/kg degC |
1 kcal/degC = 4187 J/degC |
|
|
|
| SPECIFIC HEAT |
J/kg degC
|
J/m³ degC |
|
| heat flow rate through unit area
of unit thickness of substance with unit temperatures difference between the two faces |
1 Btu/lb degF = 4.187 J/kg degC
1 Btu/ft³ degF = 67 kJ/m³ degC |
1 kcal/kg degC = 4.187 kJ/kg degC
1 kcal/m³ degC = 4.187 kJ/m³ degC
1 kcal/l degC = 4.187 MJ/m³ degC |
|
|
| THERMAL
CONDUCTIVITY |
W/m degC |
|
| heat flow rate through unit ara
of unit thickness of substance with unit temperature difference between the two faces |
1 Btu.in/ft².h.degF = 0.144 W/m
degC
1 kcal/m.h.degC = 1.163 W/m degC |
|
|
|
|
| THERMAL
TRANSMITTANCE |
W/m² degC |
|
| heat flow rate through unit area
of body with unit difference in temperature of air on the two sides |
1 Btu/ft².h.degF = 5.678 W/m²
degC
1 kcal/m².h.degC = 1.163 W/m degC |
|
|
|
|
| LATENT
HEAT, CALORIFIC VALUE |
J/kg, J/m³ |
|
| change in energy content at
change of state, or heat porduced by combustion (per uit mass or unit volume) |
1 Btu/lb = 2326 J/kg
1 Btu/ft³ = 37.26 kJ/m³
1 Btu/gal = 232 kJ/m³ |
1 kcal/kg = 4187 J/kg
1 kcal/m³ = 4187 J/m³
1 kcal/l = 4187 kJ/m³ |
|
|
|
| LUMINOUS FLUX |
Lm |
Lumen |
cd.sr |
| emitted by unit intensity source
in unit solid angle |
|
|
|
|
| ILLUMINATION |
lx |
lux |
Lm/m² |
| unit flux incident on unit area |
1 Lm/ft² = 10.76 lx |
|
|
|
| LUMINANCE |
cd/m² |
(nit) |
|
| unit intensity per unit area |
asb (apostilb)
1 cd/m² = 3.14 asb |
1 cd/ft² = 10.76 cd/m²
1 ft lambert = 10.76 asb = 3.42 cd/m² |
