Unit Conversion Factors

Note:  En = 10n, e.g., E5=105, E-5=10-5.


Specific Energy  (Heat / Volume)

J/m3

kJ/m3

kcal/m3

Btu/ft3

Chu/ft3

MJ/m3*

J/m3

1

1E-3

1.338E-4

2.684E-5

1.491E-5

1E-6

kJ/m3

1 000

1

0.238 8

0.026 84

0.014 91

1 E-3

kcal/m3

4.187E3

4.187

1

0.112 4

0.062 43

4.187E-3

Btu/ft3

3.726E4

37.26

8.899

1

0.555 6

0.037 26

Chu/ft3

6.707E4

67.07

16.02

1.800

1

0.067 07

MJ/m3

1E6

1000

238.8

26.84

14.91

1

  1 therm (105 Btu) / UK gal = 23 208 MJ/m3
  1 thermie/liter = 4.185 MJ/m3
  *MJ/m3 = J/cm3

 Heat Transfer, Temperature

Energy/unit mass

1 Btu/lbm = 2.326 kJ/kg

1 kJ/kg = 0.4299 Btu/lbm

Heat/unit area

1 Btu/hr∙ft2 = 3.154 W/m2

1 W/m2 = 0.317 Btu/hrּft2

Heat/unit length

1 Btu/hr∙ft = 0.9613 W/m

1 W/m = 1.0403 Btu/hrּft

Thermal Conductivity (κ)

1 Btu/hr∙ft∙°F = 1.7307 W/m.°C

1 W/m∙°C = 0.5778 Btu/hrּftּ°F

Convection Heat Transfer Coefficient (h)

1 Btu/hr∙ft2ּ°F = 5.6783 W/m2ּ°C

1 W/m2∙°C = 0.1761 Btu/hrּft2ּ°F

Specific Heat (Cp)

1 Btu/lbmּ°F = 4.1869 kJ/kgּ°C

1 kJ/k∙°C = 0.23884 Btu/lbmּ°F

Dynamic Viscosity (μ)

1 kg/mּs = 0.672 lbm/ftּs = 2419.2 lbm/ftּhr

1 lbm/ft∙s = 1.4881 kg/mּs

Kinematic Viscosity (ν) and Thermal Diffusivity (α)

1 ft2/s = 0.092903 m2/s

1 m2/s = 10.7639 ft2/s

Temperature (ΔT)

°R = 1.8 °K OR °F = 1.8 °C

°K = 0.556 °R OR °C = 0.556 °F

Temperature (T)

T (°F) = 1.8 * T (°C) + 32

°K = 0.556 °R OR °C = 0.556 °F

Temperature (T)

T (°R) = T (°F) + 459.67

T (°K) = T (°C) + 273.15

Stefan-Boltzmann constant (σ)

0.1714E8 Btu/hrּft2ּ°R4

5.669 E8 W/m2ּ°K4

Thermal Expansion

1 μin/in ּ°F = 1.8E-6/K

1/K = 5.556E5 μin/in ּ°F

Thermal Resistance Coefficient

1 clo = 0.15482 m2ּ°K/W

1 m2ּ°K/W = 6.459 clo

 Electric

Electric capacitance

1 jar = 1.111E-9 F (Farad)

1 F = 9.000E8 jar

a.u. of charge

1 a.u., e = 1.60218E-19 C (coulomb)

1 C = 6.241E18 a.u., e

electrostatic unit

1 esu = 3.336E-6 C 

1 C = 0.300E5 esu

franklin

1 Fr = 3.33564E-10 C 

 

a.u. of charge density

1 a.u. = 1.0812E12 C/m3 

 

coulomb per cubic inch

1 C/in3 = 6.10237E4 C/m3 

 

coulomb per square inch

C/in2 = 1550 C/m2 

 

Electric conductance

1 mho = 1 S (siemens)

1 S = 1 mho

Electric conductivity

1 roc = 100 S/m = 100 rom

 

Electric current

1 a.u. = 6.624E-3 A = 6.624E-3 C/s

Electric dipole moment

1 a. u. = 8.478E-30 C-m

 

electric field strength

1 a. u. = 5.142E11 V/m = 5.142E11 N/C

Electric inductance

1 J/A2 = N-m/A2 = 1 H = V·s/A

 

Electric permittivity

1 A·s/V·m = 1 C2/N·m2 = 1 F/m

Electric potential

1 a. u. = 27.21 V = 27.21 J/C, 1 statV = 299.792 V

Electric resistance

1 siemens (resistance) = 0.96 Ω, 1 statohm = 8.988E11 Ω

Molar electric charge

1 F (Faraday) = 9.65E4 C/mol

1 C/mol = 1.036E-5

 Magnetic

Electromagnetic radiation flux density

1 jansky = 1E-26 W/m2-Hz 

Magnetic auxiliary field

1 oe (oersted) = 79.5775 A/m, 1 praoersted = 1.14591E4 A/m 

Magnetic dipole moment

1 a.u. = 1.855E-23 A?m2 = 1.855E-23 J/T 

Magnetic field strength

1 a.u. = 2.351E5 T = 2.351E5 N/A?m = 2.351E14 g = 2.351E9 Gs

Magnetic flux

1 line = 1 Mx = 1E-8 Wb = 7.958E-2 unit pole

Magnetic permeability

1 V?s/A?m = 1 N/A2 = 1 H/m

Magnetomotive force

Gb = 0.79577 A, 1 pragilbert = 1.146E4 A

 Recommended SI Units For Properties of Steel

PHYSICAL PROPERTIES  

 

Density
Specific heat  
Heat content
Thermal conductivity
Thermal expansion

kg/m3
kJ/kg K
kJ/kg
W/m K
microstrain/K  

ELECTRICAL PROPERTIES

 

Resistivity
Magnetic field strength
Magnetic induction
Specific magnetic permeability

Ωm
A/m
T
(Given as pure number)

MECHANICAL PROPERTIES

 

Tensile strength
Proof (or yield) stress  
Young's modulus
Impact strength  
Impact strength
Elongation

Reduction in area

N/mm2 (MN/m2)
N/mm2 (MN/m2)
N/mm2 (MN/m2)
J
MNm-3/2
(Given as percentage on a gauge length, equals 5.65S01/2 ,
S0= nominal cross sectional area)  
(Given as a % of original area)