The following tables identify the preferred SI/metric units, along with conversion factors from customary units. Nomenclature for these tables
Contents
1 Space, time
2 Mass, amount of substance
3 Calorific value, heat, entropy, heat capacity
4 Temperature, pressure, vacuum
5 Density, specific volume, concentration, dosage
6 Facility throughput, capacity
7 Flow rate
8 Energy, work, power
9 Mechanics
10 Transport properties
11 Electricity, magnetism
12 Acoustic, light, radiation
13 References
14 See also
15 Category
Space, time
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Length
m
naut mile
km
1.852* E+00
mile
km
1.609 344* E+00
chain
m
2.011 68* E+01
link
m
2.011 68* E−01
fathom
m
1.828 8* E+00
m
m
1.0* E+00
yd
m
9.144* E−01
ft
m
3.048* E−01
cm
3.048* E+01
in.
mm
2.54* E+01
cm
2.54* E+00
cm
mm
1.0* E+01
cm
1.0* E+00
mm
mm
1.0 E+00
mil
μm
2.54* E+01
micron (μ)
μm
1.0* E+00
Length/length
m/m
ft/mi
m/km
1.893 939 E−01
Length/volume
m/m3
ft/U.S. gal
m/m3
8.051 964 E+01
ft/ft3
m/m3
1.076 391 E+01
ft/bbl
m/m3
1.917 134 E+00
Area
m2
sq mile
km2
2.589 988 E+00
section
km2
2.589 988 E+00
ha
2.589 988 E+02
acre
m2
4.046 856 E+03
ha
4.046 856 E−01
ha
m2
1.0* E+04
sq yd
m2
8.361 274 E−01
sq ft
m2
9.290 304* E−02
cm2
9.290 304* E+02
sq in.
mm2
6.451 6* E+02
cm2
6.451 6* E+00
cm2
mm2
1.0* E+02
cm2
1.0* E+00
mm2
mm2
1.0* E+00
Area/volume
m2 /m3
ft2
m2 /cm3
5.699 291 E−03
Area/mass
m2 /kg
cm
m2 /kg
1.0* E−01
m2 /g
1.0* E−04
Volume, capacity
m3
cubem
km3
4.168 182 E+00[1] †
acre-ft
m3
1.233 489 E+03
ha•m
1.233 489 E−01
m3
m3
1.0* E+00
cu yd
m3
7.645 549 E−01
bbl (42 U.S. gal)
m3
1.589 873 E−01
cu ft
m3
2.831 685 E−02
dm3
L
2.831 685 E+01
U.K. gal
m3
4.546 092 E−03
dm3
L
4.546 092 E+00
U.S. gal
m3
3.785 412 E−03
dm3
L
3.785 412 E+00
liter
dm3
L
1.0* E+00
U.K. qt
dm3
L
1.136 523 E+00
U.S. qt
dm3
L
9.463 529 E−01
U.S. pt
dm3
L
4.731 765 E−01
Volume, capacity
m3
U.K. fl oz
cm3
2.841 308 E+01
U.S. fl oz
cm3
2.957 353 E+01
cu in.
cm3
1.638 706 E+01
mL
cm3
1.0* E+00
Volume/length (linear displacement)
m3 /m
bbl/in.
m3 /m
6.259 342 E+00
bbl/ft
m3 /m
5.216 119 E−01
ft3 /ft
m3 /m
9.290 304* E−02
U.S. gal/ft
m3 /m
1.241 933 E−02
dm3 /m
L/m
1.241 933 E+01
Plane angle
rad
rad
rad
1.0* E+00
deg (°)
rad
1.745 329 E−02[2]
°
1.0* E+00
min (’)
rad
2.908 882 E−04[2]
’
1.0* E+00
sec (’’)
rad
4.848 137 E−06[2]
’’
1.0* E+00
Solid angle
sr
sr
sr
1.0* E+00
Time
s
million years (MY)
Ma
1.0* E+00[3]
yr
a
1.0* E+00
wk
d
7.0* E+00
d
d
1.0* E+00
hr
h
1.0* E+00
min
6.0* E+01
min
s
6.0* E+01
h
1.666 667 E−02
min
1.0* E+00
s
s
1.0* E+00
millimicrosecond
ns
1.0* E+00
Mass, amount of substance
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Mass
kg
U.K. ton (long ton)
Mg
t
1.016 047 E+00
U.S. ton (short ton)
Mg
t
9.071 847 E−01
U.K. ton
kg
5.080 235 E+01
U.S. cwt
kg
4.535 924 E+01
kg
kg
1.0* E+00
lbm
kg
4.535 924 E−01
oz (troy)
g
3.110 348 E+01
oz (av)
g
2.834 952 E+01
g
g
1.0* E+00
grain
mg
6.479 891 E+01
mg
mg
1.0* E+00
g
g
1.0* E+00
Amount of substance
mol
lbm mol
kmol
4.535 924 E−01
g mol
kmol
1.0* E−03
std m3 (0°C, 1 atm)
kmol
4.461 58 E−02[4] [5]
std m3 (15°C, 1 atm)
kmol
4.229 32 E−02[4] [5]
std ft3 (60°F, 1 atm)
kmol
1.195 3 E−03[4] [5]
Calorific value, heat, entropy, heat capacity
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Calorific value (mass basis)
J/kg
Btu/lbm
MJ/kg
2.326 E−03
kJ/kg
J/g
2.326 E+00
(kW•h)/kg
6.461 112 E−04
cal/g
kJ/kg
J/g
4.184* E+00
cal/lbm
J/kg
9.224 141 E+00
Calorific value (mole basis)
J/mol
kcal/g mol
kJ/kmol
4.184* C+03[5]
Btu/lbm mol
MJ/kmol
2.326 E−03[5]
kJ/kmol
2.326 E+00[5]
Calorific value(volume basis–solids and liquids)
J/m3
therm/U.K. gal
MJ/m3
kJ/dm3
2.320 80 E+04
kJ/m3
2.320 80 E+07
(kW•h)/dm3
6.446 660 E+00
Btu/U.S. gal
MJ/m3
kJ/dm3
2.787 163 E−01
kJ/m3
2.787 163 E+02
(kW•h)/m3
7.742 119 E−02
Btu/U.K. gal
MJ/m3
kJ/dm3
2.320 8 E−01
kJ/m3
2.320 8 E+02
(kW•h)/m3
6.446 660 E−02
Btu/ft3
MJ/m3
kJ/dm3
3.725 895 E−02
kJ/m3
3.725 895 E+01
(kW•h)/m3
1.034 971 E−02
kcal/m3
MJ/m3
kJ/dm3
4.184* E−03
kJ/m3
4.184* E−03
cal/mL
MJ/m3
4.184* E+00
ft-lbf/U.S. gal
kJ/m3
3.581 692 E−01
Calorific value (volume basis–gases)
J/m3
cal/mL
kJ/m3
J/dm3
4.184* E+03
kcal/m3
kJ/m3
J/dm3
4.184* E+00
Btu/ft3
kJ/m3
J/dm3
3.725 895 E+01
(kW•h)/m3
1.034 971 E−02
Specific entropy
J/kg•K
Btu/(lbm-°R)
kJ(kg•K)
J(g•K)
4.186 8* E+00
cal/(g-°K)
kJ(kg•K)
J(g•K)
4.184* E+00
kcal/(kg-°C)
kJ(kg•K)
J(g•K)
4.184* E+00
Specific heat
J/kg•K
kW-hr/(kg-°C)
kJ(kg•K)
J(g•K)
3.6* E+03
capacity (mass basis)
Btu/(lbm-°F)
kJ(kg•K)
J(g•K)
4.186 8* E+00
kcal(kg-°C)
kJ(kg•K)
J(g•K)
4.184* E+00
Molar heat
J/mol•K
Btu/(lbm mol-°F)
kJ(kmol•K)
4.186 8* E+00[5]
capacity
cal/(g mol-°C)
kJ(kmol•K)
4.184* E−00[5]
Temperature, pressure, vacuum
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Temperature (absolute)
K
°R
K
5/9
°K
K
1.0* E+00
Temperature (traditional)
K
°F
°C
(F−32)/1.8
°C
°C
1.0* E+00
Temperature (difference)
K
°F
K
°C
5/9 E+00
°C
K
°C
1.0* E+00
Temperature/length (geothermal gradient)
K/m
°F/100 ft
mK/m
1.822 689 E+01
Length/temperature (geothermal step)
m/K
ft°F
m/K
5.486 4* E−01
Pressure
Pa
atm (760 mm Hg at 0°C or 14.696 (lbf/in.2)
MPa
1.013 25* E−01
kPa
1.013 25* E+02
bar
1.013 25* E+00
bar
MPa
1.0* E−01
kPa
1.0* E+02
bar
1.0* E+00
at (technical atm, kbf/cm2)
MPa
9.806 65* E−02
kPa
9.806 65* E+01
bar
9.806 65* E−01
Pressure
Pa
lbf/in.2 (psi)
MPa
6.894 757 E−03
kPa
6.894 757 E+00
bar
6.894 757 E−02
in. Hg (32°F)
kPa
3.386 38 E+00
in. Hg (60°F)
kPa
3.376 85 E+00
in. H2O (39.2°F)
kPa
2.490 82 E−01
in. H2O (60°F)
kPa
2.488 4 E−01
Mm Hg (0°C)=torr
kPa
1.333 224 E−01
Cm H2O (4°C)
kPa
9.806 38 E−02
lbf/ft2 (psf)
kPa
4.788 026 E−02
µm Hg (0°C)
Pa
1.333 224 E−01
µbar
Pa
1.0* E−01
dyne/cm2
Pa
1.0* E−01
Vacuum, draft
Pa
in. Hg (60°F)
kPa
3.376 85 E+00
in. H2O (39.2°F)
kPa
2.490 82 E−01
Mm Hg (0°C)=torr
kPa
1.333 224 E−01
Cm H2O (4°C)
kPa
9.806 38 E−02
Liquid heat
m
ft
m
3.048* E−01
in.
mm
2.54* E+01
cm
2.54* E+00
Pressure drop/length
Pa/m
psi/ft
kPa/m
2.262 059 E+01
psi/100 ft
kPa/m
2.262 059 E−01
Density, specific volume, concentration, dosage
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Density (gases)
kg/m3
lbm/ft3
kg/m3
1.601 846 E+01
g/m3
1.601 846 E+04
Density (liquids)
kg/m3
lbm/U.S. gal
kg/m3
1.198 264 E+02
g/cm3
1.198 264 E−01
lbm/U.K. gal
kg/m3
9.997 633 E+01
kg/dm3
9.977 633 E−02
lbm/ft3
kg/m3
1.601 846 E+01
g/cm3
1.601 846 E−02
g/cm3
kg/m3
1.0* E+03
kg/dm3
1.0* E+00
°API
g/cm3
141.5/(131.5+°API)
Density (solids)
kg/m3
lbm/ft3
kg/m3
1.601 846 E+01
Specific volume(gases)
m3 /kg
ft3 /lbm
m3 /kg
6.242 796 E−02
m3 /g
6.242 796 E−05
Specific volume (liquids)
m3 /kg
ft3 /lbm
dm3 /kg
6.242 796 E+01
U.K. gal/lbm
dm3 /kg
cm3 /g
1.002 242 E+01
U.S. gal/lbm
dm3 /kg
cm3 /g
8.345 404 E+00
Specific volume (mole basis)
ft3 /mol
L/g mol
m3 /kmol
1.0* E+00[5]
ft3 /lbm mol
m3 /kmol
6.242 796 E−02[5]
Specific volume (clay yield)
m3 /kg
bbl/U.S. ton
m3 /t
1.752 535 E−01
bbl/U.K. ton
m3 /t
1.564 763 E−01
Yield (shale distillation)
m3 /kg
bbl/U.S. ton
dm3 /t
L/t
1.752 535 E+02
bbl/U.K. ton
dm3 /t
L/t
1.564 763 E+02
U.S. gal/U.S. ton
dm3 /t
L/t
4.172 702 E+00
U.S. gal/U.K. ton
dm3 /t
L/t
3.725 627 E+00
Concentration(mass/mass)
kg/kg
wt%
kg/kg
1.0* E−02
g/kg
1.0* E+01
wt ppm
mg/kg
1.0* E+00
Concentration(mass/volume)
kg/m3
lbm/bbl
kg/m3
g/dm3
2.853 010 E+00
g/U.S. gal
kg/m3
2.641 720 E−01
g/U.K. gal
kg/m3
g/L
2.199 692 E−01
Concentration(mass volume)
kg/m3
lbm/1,000 U.S. gal
g/m3
mg/dm3
1.198 264 E+02
lbm/1,000 U.K. gal
g/m3
mg/dm3
9.977 633 E+01
grains/U.S. gal
g/m3
mg/dm3
1.711 806 E+01
grains/ft3
mg/m3
2.288 352 E+03
lbm/1,000 bbl
g/m3
mg/dm3
2.853 010 E+00
mg/U.S. gal
g/m3
mg/dm3
2.641 720 E−01
grains/100 ft3
mg/m3
2.288 352 E+01
Concentration(volume/volume)
m3 / m3
bbl/bbl
m3 /m3
1.0* E+00
ft3 /ft3
m3 /m3
1.0* E+00
bbl/acre-ft
m3 /m3
1.288 923 E−04
m3 /ha•m
1.288 923 E+00
vol %
m3 /m3
1.0* E−02
U.K. gal/ft3
dm3 /m3
L/m3
1.605 437 E+02
U.S. gal/ft3
dm3 /m3
L/m3
1.336 806 E+02
mL/U.S. gal
dm3 /m3
L/m3
2.641 720 E−01
mL/U.K. gal
dm3 /m3
L/m3
2.199 692 E−01
vol ppm
cm3 /m3
1.0* E+00
dm3 /m3
L/m3
1.0* E−03
U.K. gal/1,000 bbl
cm3 /m3
1.859 406 E+01
U.S. gal/1,000 bbl
cm3 /m3
2.380 952 E+01
U.K. pt/1,000 bbl
cm3 /m3
3.574 253 E+00
Concentration
mol/m3
lbm mol/U.S. gal
kmol/m3
1.198 264 E+02
lbm mol/U.K. gal
kmol/m3
9.977 633 E+01
lbm mol/ft3
kmol/m
1.601 846 E+01
std ft3 (60°F,1 atm)/bbl
kmol/m3
7.518 18 E−03
Concentration(volume/mole)
m3/mol
U.S. gal/1,000 std ft3 (60°F/60°F)
dm3/kmol
L/kmol
3.166 93 E+00
bbl/million std ft3 (60°F/60°F)
dm3/kmol
L/kmol
1.330 11 E−01
Facility throughput, capacity
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Throughput (mass basis)
kg/s
million lbm/yr
t/a
Mg/a
4.535 924 E+02
U.K. ton/yr
t/a
Mg/a
1.016 047 E+00
U.S. ton/yr
t/a
Mg/a
9.071 847 E−01
U.K. ton/D
t/d
Mg/d
1.016 047 E+00
t/h, Mg/h
4.233 529 E−02
U.S. ton/D
t/d
9.071 847 E−01
t/h, Mg/h
3.779 936 E−02
U.K. ton/hr
t/h
Mg/h
1.016 047 E+00
U.S. ton/hr
t/h
Mg/h
9.071 847 E−01
lbm/hr
kg/h
4.535 924 E−01
Throughput (volume basis)
m3 /s
bbl/D
t/a
5.803 036 E+01[6]
m3 /d
1.589 873 E−01
m3 /h
6.624 471 E−03
ft3 /D
m3 /d
2.831 685 E−02
bbl/hr
m3 /h
1.589 873 E−01
ft3 /h
m3 /h
2.831 685 E−02
U.K. gal/hr
m3 /h
4.546 092 E−03
L/s
1.262 803 E−03
U.S. gal/hr
m3 /h
3.785 412 E−03
L/s
1.051 503 E−03
U.K. gal/min
m3 /h
2.727 655 E−01
L/s
7.576 819 E−02
U.S. gal/min
m3 /h
2.271 247 E−01
L/s
6.309 020 E−02
Throughput (mole basis)
mol/s
lbm mol/hr
kmol/h
4.535 924 E−01
kmol/s
1.259 979 E−04[7]
Pipeline capacity
m3 /m
bbl/mile
m3 /km
9.879 013 E−02
Flow rate (mass basis)
kg/s
U.K. ton/min
kg/s
1.693 412 E+01
U.S. ton/min
kg/s
1.511 974 E+01
U.K. ton/hr
kg/s
2.822 353 E−01
U.S. ton/hr
kg/s
2.519 958 E−01
U.K. ton/D
kg/s
1.175 980 E−02
U.S. ton/D
kg/s
1.049 982 E−02
million lbm/yr
kg/s
5.249 912 E+02
U.K. ton/yr
kg/s
3.221 864 E−05
U.S. ton/yr
kg/s
2.876 664 E−05
lbm/s
kg/s
4.535 924 E−01
lbm/min
kg/s
7.559 873 E−03
lbm/hr
kg/s
1.259 979 E−04
Flow rate (volume basis)
m3 /s
bbl/D
m3 /d
1.589 873 E−01
L/s
1.840 131 E−03
ft3 /D
m3 /d
2.831 685 E−02
L/s
3.277 413 E−04
bbl/hr
m3/s
4.416 314 E−05
L/s
4.416 314 E−02
ft3 /hr
m3 /s
7.865 791 E−06
L/s
7.865 791 E−03
U.K. gal/hr
dm3 /s
L/s
1.262 803 E−03
U.S. gal/hr
dm3 /s
L/s
1.051 503 E−03
U.K. gal/min
dm3 /s
L/s
7.576 820 E−02
U.S. gal/min
dm3/s
L/s
6.309 020 E−02
ft3 /min
dm3 /s
L/s
4.719 474 E−01
ft3 /s
dm3 /s
L/s
2.831 685 E+01
Flow rate (mole basis)
mol/s
lbm mol/s
kmol/s
4.535 924 E−0113
lbm mol/hr
kmol/s
1.259 979 E−0413
million scf/D
kmol/s
1.383 449 E−0213
Flow rate/length (mass basis)
kg/s•m
lbm/(s-ft)
kg/(s•m)
1.488 164 E+00
lbm/(hr-ft)
kg/(s•m)
4.133 789 E−04
Flow rate/length
m2 /s
U.K. gal/(min-ft)
m2 /s
m3 /(s•m)
2.485 833 E−04
U.S. gal/(min-ft)
m2 /s
m3 /(s•m)
2.069 888 E−04
U.K. gal/(hr-in.)
m2 /s
m3 /(s•m)
4.971 667 E−05
U.S. gal/(hr-in.)
m2 /s
m3 /(s•m)
4.139 776 E−05
U.K. gal/(hr-ft)
m2 /s
m3 /(s•m)
4.143 055 E−06
U.S. gal/(hr-ft)
m2 /s
m3 /(s•m)
3.449 814 E−06
Flow rate/area (mass basis)
kg/s•m2
lbm/(s-ft2 )
kg/s•m2
4.882 428 E+00
lbm/(hr-ft2)
kg/s•m2
1.356 230 E−03
Flow rate
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Flow rate/area
m/s
ft3 /(s-ft2 )
m/s
m3 /(s•m2 )
3.048* E−01
ft3 /(min-ft2 )
m/s
m3 /(s•m2 )
5.08* E−03
U.K. gal/(hr-in.2 )
m/s
m3 /(s•m2 )
1.957 349 E−03
U.S. gal/(hr-in.2 )
m/s
m3 /(s•m2 )
1.629 833 E−03
U.K. gal/(min-ft2 )
m/s
m3 /(s•m2 )
8.155 621 E−04
U.S. gal/(min-ft2 )
m/s
m3 /(s•m2 )
6.790 972 E−04
U.K. gal/(hr-ft2 )
m/s
m3 /(s•m2 )
1.359 270 E−05
U.S. gal/(hr-ft2 )
m/s
m3 /(s•m2 )
1.131 829 E−05
Flow rate/pressure drop (productivity index)
m3 /s•Pa
bbl/(D-psi)
m3 /(d•kPa)
2.305 916 E−02
Energy, work, power
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Energy, work
J
quad
MJ
1.055 056 E+12
TJ
1.055 056 E+06
EJ
1.055 056 E+00
MW•h
2.930 711 E+08
GW•h
2.930 711 E+05
TW•h
2.930 711 E+02
therm
MJ
1.055 056 E+02
kJ
1.055 056 E+05
kW•h
2.930 711 E+01
U.S. tonf-mile
MJ
1.431 744 E+01
hp-hr
MJ
2.684 520 E+00
kJ
2.684 520 E+03
kW•h
7.456 999 E−01
ch-hr or CV-hr
MJ
2.647 796 E+00
Kj
2.647 796 E+03
kW•h
7.354 99 E−01
kW-hr
MJ
3.6* E+00
kJ
3.6* E+03
Chu
kJ
1.899 101 E+00
kW•h
5.275 280 E−04
Btu
kJ
1.055 056 E+00
kW•h
2.930 711 E−04
kcal
kJ
4.184* E+00
cal
kJ
4.184* E−03
ft-lbf
kJ
1.344 818 E−03
lbf-ft
kJ
1.355 818 E−03
J
kJ
1.0* E−03
lbf-ft2 /s2
kJ
4.214 011 E−05
erg
J
1.0* E−07
Impact energy
J
kgf•m
J
9.806 650* E+00
lbf-ft
J
1.355 818 E+00
Work/length
J/m
U.S. tonf-mile/ft
MJ/m
4.697 322 E+01
Surface energy
J/m2
erg/cm2
mJ/m2
1.0* E+00
Specific impact
J/m2
kgf•m/cm2
J/cm2
9.806 650* E−00
energy Power
lbf•ft/in.2
J/cm2
2.101 522 E−01
W
quad/yr
MJ/a
1.055 056 E+12
TJ/a
1.055 056 E+06
EJ/a
1.055 056 E+00
erg/a
TW
3.170 979 E−27
GW
3.170 979 E−24
million Btu/hr
MW
2.930 711 E−01
ton of refrigeration
kW
3.516 853 E+00
Btu/s
kW
1.055 056 E+00
kW
kW
1.0* E+00
hydraulic horsepower—hhp
kW
7.460 43 E−01
hp (electric)
kW
7.46* E−01
hp (550 ft-lbf/s)
kW
7.456 999 E−01
ch or CV
kW
7.354 99 E−01
Btu/min
kW
1.758 427 E−02
ft•lbf/s
kW
1.355 818 E−03
kcal/hr
W
1.162 222 E+00
Btu/hr
W
2.930 711 E−01
ft•lbf/min
W
2.259 697 E−02
Power/area
W/m2
Btu/s•ft2
kW/m2
1.135 653 E+01
cal/hr•cm2
kW/m2
1.162 222 E−02
Btu/hr•ft2
kW/m2
3.154 591 E−03
Heat flow unit—hfu
µcal/s•cm2
mW/m2
4.184* E+01
(geothermics)
Heat release rate,
W/m2
hp/ft3
kW/m3
2.633 414 E+01
mixing power
cal/(hr•cm3 )
kW/m3
1.162 222 E+00
Btu/(s•ft3 )
kW/m3
3.725 895 E+01
Btu/(hr•ft3 )
kW/m3
1.034 971 E−02
Heat generation unit—hgu (radioactive rocks)
cal/(s•cm3 )
µW/m3
4.184* E+12
Cooling duty (machinery)
W/W
Btu/(bhp-hr)
W/kW
3.930 148 E−01
Specific fuel consumption (mass basis)
kg/J
lbm/(hp-hr)
mg/J
kg/MJ
1.689 659 E−01
kg/(kW•h)
6.082 774 E−01
Specific fuel consumption (volume basis)
m3 /J
m3 /(kW-hr)
dm3 /MJ
mm3 /J
2.777 778 E+02
dm3 /(kW•h)
1.0* E+03
U.S. gal/(hp-hr)
dm3 /MJ
mm3 /J
1.410 089 E+00
dm3 (kW•h)
5.076 321 E+00
U.K. pt/(hp-hr)
dm3 /MJ
mm3/J
2.116 809 E−01
dm3 /(kW•h)
7.620 512 E−01
Fuel consumption (automotive)
m3 /m
U.K. gal/mile
dm3/100 km
L/100 km
2.824 811 E+02
U.S. gal/mile
dm3 /100 km
L/100 km
2.352 146 E+02
mile/U.S. gal
km/dm3
km/L
4.251 437 E−01
mile/U.K. gal
km/dm3
km/L
3.540 060 E−01
Mechanics
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Velocity (linear),
m/s
knot
km/h
1.852* E+00
speed
mile/hr
km/h
1.609 344* E+00
m/s
m/s
1.0* E+00
ft/s
m/s
3.048* E−01
cm/s
3.048* E+01
m/ms
3.048* E−04[8]
ft/min
m/s
5.08* E−03
cm/s
5.08* E−01
ft/hr
mm/s
8.466 667 E−02
cm/s
8.466 667 E−03
ft/D
mm/s
3.527 778 E−03
m/d
3.048* E−01
in.
mm/s
2.54* E+01
cm/s
2.54* E+00
in./min
mm/s
4.233 333 E−01
cm/s
4.233 333 E−02
Velocity (angular)
rad/s
rev/min
rad/s
1.047 198 E−01
rev/s
rad/s
6.283 185 E+00
degree/min
rad/s
2.908 882 E−04
Interval transit time
s/m
s/ft
s/m
µs/m
3.280 840 E+00[9]
Corrosion rate
m/s
in./yr (ipy)
mm/a
2.54* E+01
mil/yr
mm/a
2.54* E−02
Rotational frequency
rev/s
rev/s
rev/s
1.0* E+00
rev/min
rev/s
1.666 667 E−02
rev/min
rad/s
1.047 198 E−01
Acceleration (linear)
m/s2
ft/s2
m/s2
3.048* E−01
cm/s2
3.048* E+01
gal(cm/s2 )
m/s2
1.0* E−02
Acceleration(rotational)
rad/s2
rad/s2
rad/s2
1.0* E+00
rpm/s
rad/s2
1.047 198 E−01
Momentum
kg•m/s
lbm•ft/s
kg•m/s
1.382 550 E−01
Force
N
U.K. tonf
kN
9.964 016 E+00
U.S. tonf
kN
8.896 443 E+00
kgf (kp)
N
9.806 650* E+00
lbf
N
4.448 222 E+00
N
N
1.0* E+00
pdl
mN
1.382 550 E+02
dyne
mN
1.0* E−02
Bending moment,
N•m
U.S. tonf-ft
kN•m
2.711 636 E+00[10] )
torque
kgf-m
N•m
9.806 650* E+00[10]
lbf-ft
N•m
1.355 818 E+00[10]
lbf-in.
N•m
1.129 848 E−01[10]
pdl-ft
N•m
4.214 011 E−02[10]
Bending moment/
N•m/m
(lbf-ft)/in.
(N•m)/m
5.337 856 E+01[10]
length
(kgf-m)/m
(N•m)/m
9.806 650* E+00[10]
(lbf-in.)/in.
(N•m)/m
4.448 222 E+00[10]
Elastic modul (Young’s, shear bulk)
Pa
lbf/in.2
GPa
6.894 757 E−06
Moment of inertia
kg•m2
lbm-ft2
kg•m2
4.214 011 E−02
Moment of section
m4
in.4
cm4
4.162 314 E+01
Section modulus
m3
cu in.
cm3
1.638 706 E+01
cu ft
cm3
1.638 706 E+04
mm3
2.831 685 E+04
m3
2.831 685 E−02
Stress
Pa
U.S. tonf/in.2
MPa
N/mm2
1.378 951 E+01
kgf/mm2
MPa
N/mm2
9.806 650* E+00
U.S. tonf/ft2
MPa
N/mm2
9.576 052 E−02
lbf/in.2 (psi)
MPa
N/mm2
6.894 757 E−03
lbf/ft2 (psf)
kPa
4.788 026 E−02
dyne/cm2
Pa
1.0* E−01
Yield point, gel strength (drilling fluid)
lbf/100 ft2
Pa
4.788 026 E−01
Mass/length
kg/m
lbm/ft
kg/m
1.488 164 E+00
Mass/area
kg/m2
U.S. ton/ft2
Mg/m2
9.764 855 E+00
structural loading, bearing capacity (mass basis)
lbm/ft2
kg/m2
4.882 428 E+00
Coefficient of thermal expansion
m/(m•K)
in./(in.-°F)
mm/(mm•K)
5.555 556 E−01
Transport properties
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Diffusivity
m2 /s
ft2 /s
mm2 /s
9.290 304* E+04
cm2 /s
mm2 /s
1.0* E+02
ft2 /hr
mm2 /s
2.580 64* E+01
Thermal resistance
(k•m2 )/W
(°C-m2 •hr)/kcal
(K•m2 )kW
8.604 208 E+02
(°F-ft2 hr)/Btu
(K•m2 )kW
1.761 102 E+02
Heat flux
W/m2
Btu/(hr-ft2 )
kW/m2
3.154 591 E−03
Thermal conductivity
W/(m•K)
(cal/s-cm2 -°C/cm
W/(m•K)
4.184* E+02
Btu/(hr-ft2 -°F/ft)
W/(m•K)
1.730 735 E+00
kJ•m/(h•m2 K)
6.230 646 E+00
kcal/(hr-m2 -°C/m)
W/(m•K)
1.162 222 E+00
Btu/(hr-ft2 -°F/in.)
W/(m•K)
1.442 279 E−01
cal/(hr-cm2 -°C/cm)
W/(m•K)
1.162 222 E−01
Heat transfer coefficient
W/(m2 •K)
cal/(s-cm2 -°C)
kW/(m2 •K)
4.184* E+01
Btu/(s-ft2 -°F)
kW/(m2 •K)
2.044 175 E+01
cal/(hr-cm2 -°C)
kW/(m2 •K)
1.162 222 E−02
Btu/(hr-ft2 -°F)
kW/(m2 •K)
5.678 263 E−03
kJ(h•m2 •K)
2.044 175 E+01
Btu/(hr-ft2 -°R)
kW/(m2 •K)
5.678 263 E−03
kcal/(hr-m2 -°C)
kW/(m2 •K)
1.162 222 E−03
Volumetric heat
kW/(m3 •K)
Btu/(s-ft3 -°F)
kW/(m3 •K)
6.706 611 E+01
transfer coefficient
Btu/(hr-ft3 -°F)
kW/(m3 •K)
1.862 947 E−02
Surface tension
N/m
dyne/cm
mN/m
1.0* E+00
Viscosity (dynamic)
Pa•s
(lbf-s)/in.2
Pa•s
(N•s)/m2
6.894 757 E+03
(lbf-s)/ft2
Pa•s
(N•s)/m2
4.788 026 E+01
(kgf-s)/m2
Pa•s
(N•s)/m2
9.806 650* E+00
lbm/(ft-s)
Pa•s
(N•s)/m2
1.488 164 E+00
(dyne-s)/cm2
Pa•s
(N•s)/m2
1.0* E−01
cp
Pa•s
(N•s)/m2
1.0* E−03
lbm/(ft-hr)
Pa•s
(N•s)/m2
4.133 789 E−04
Viscosity (kinematic)
m2 /s
ft2 /s
mm2 /s
9.290 304* E+04
in.2 /s
mm2 /s
6.451 6* E+02
m2 /hr
mm2 /s
2.777 778 E+02
cm2 /s
mm2 /s
1.0* E+02
ft2 /hr
mm2 /s
2.580 64* E+01
cSt
mm2 /s
1.0* E+00
Permeability
m2
darcy
μm2
9.869 233 E−01[11]
millidarcy
μm2
9.869 233 E−04[11]
10−3 μm2
9.869 233 E−01[11]
Electricity, magnetism
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Admittance
S
S
S
1.0* E+00
Capacitance
F
μF
μF
1.0* E+00
Capacity, storage battery
C
A•hr
kC
3.6* E+00
Charge density
C/m3
C/mm3
C/mm3
1.0* E+00
Conductance
S
S
S
1.0* E+00
Ω(mho)
S
1.0* E+00
Conductivity
S/m
S/m
S/m
1.0* E+00
Ω/m
S/m
1.0* E+00
m Ω/m
mS/m
1.0* E+00
Current density
A/m2
A/mm2
A/mm2
1.0* E+00
Displacement
C/m2
C/cm2
C/cm2
1.0 E+00
Electric charge
C
C
C
1.0* E+00
Electric current
A
A
A
1.0* E+00
Electric dipole moment
C•m
C•m
C•m
1.0* E+00
Electric field strength
V/m
V/m
V/m
1.0* E+00
Electric flux
C
C
C
1.0* E+00
Electric polarization
C/m2
C/m2
C/m2
1.0* E+00
Electric potential
V
V
V
1.0* E+00
mV
mV
1.0* E+00
Electromagnetic moment
A•m2
A•m2
A•m2
1.0* E+00
Electromotive force
V
V
V
1.0* E+00
Flux of displacement
C
C
C
1.0* E+00
Frequency
Hz
cycles/s
Hz
1.0* E+00
Impedance
Ω
Ω
Ω
1.0* E+00
Interval transit time
s/m
μs/ft
μs/m
3.280 840 E+00
Linear current density
A/m
A/mm
A/mm
1.0* E+00
Magnetic dipole moment
Wb•m
Wb•m
Wb•m
1.0* E+00
Magnetic field strength
A/m
A/mm
A/mm
1.0* E+00
oersted
A/m
7.957 747 E+01
gamma
A/m
7.957 747 E−04
Magnetic flux
Wb
mWb
mWb
1.0* E+00
Magnetic flux density
T
mT
mT
1.0* E+00
gauss
T
1.0* E−04
Magnetic induction
T
mT
mT
1.0* E+00
Magnetic moment
A•m2
A•m2
A•m2
1.0* E+00
Magnetic polarization
T
mT
mT
1.0* E+00
Magnetic potential difference
A
A
A
1.0* E+00
Magnetic vector potential
Wb/m
Wb/m
Wb/m
1
Magnetization
A/m
A/mm
A/mm
1
Modulus of admittance
S
S
S
1
Modulus of impedance
Ω
Ω
Ω
1
Mutual inductance
H
H
H
1
Permeability
H/m
µH/m
µH/m
1
Permeance
H
H
H
1
Permittivity
F/m
µF/m
µF/m
1
Potential difference
V
V
V
1
Quantity of electricity
C
C
C
1
Reactance
Ω
Ω
Ω
1
Reluctance
H–1
H–1
H–1
1
Resistance
Ω
Ω
Ω
1
Resistivity
Ω•m
Ω•cm
Ω•cm
1
Ω•m
Ω•m
1 [12]
Self inductance
H
mH
mH
1
Surface density of charge
C/m2
mC/m2
mC/m2
1
Susceptance
S
S
S
1
Volume density of charge
C/m3
C/mm3
C/mm3
1
Acoustic, light, radiation
Quantity
SI Unit
Customary Unit
Metric Unit SPE Preferred
Metric Unit Other Allowable
Conversion Factor:*Multiply Customary Unit by Factor To Get Metric Unit
Absorbed dose
Gy
rad
Gy
1.0* E−02
Acoustical energy
J
J
J
1
Acoustical intensity
W/m2
W/cm2
W/m2
1.0* E+04
Acoustical power
W
W
W
1
Sound pressure
N/m2
N/m2
N/m2
1
Illuminance
lx
footcandle
lx
1.076 391 E+01
Illumination
lx
footcandle
lx
1.076 391 E+01
Irradiance
W/m2
W/m2
W/m2
1
Light exposure
lx•s
footcandle•s
lx•s
1.076 391 E+01
Luminance
cd/m2
cd/m2
cd/m2
1
Luminous efficacy
lm/W
lm/W
lm/W
1
Luminous exitance
lm/m2
lm/m2
lm/m2
1
Luminous flux
lm
lm
lm
1
Luminous intensity
cd
cd
cd
1
Quantity of light
ℓm•s
talbot
ℓm•s
1.0* E+00
Radiance
W/(m2 •sr)
W/(m2 •sr)
W/(m2 •sr)
1
Radiant energy
J
J
J
1
Radiant flux
W
W
W
1
Radiant intensity
W/sr
W/sr
W/sr
1
Radiant power
W
W
W
1
Wavelength
m
Å
nm
1.0* E−01
Capture unit
m−1
10−3 cm−1
m−1
1.0* E+01
10−3 cm−1
1
m−1
m−1
1
Radioactivity
curie
Bq
3.7* E+10
Capillary
Pa
ft (fluid)
m (fluid)
3.048* E−01
Compressibility of
Pa−1
psi−1
Pa−1
1.450 377 E−04
reservoir fluid
kPa−1
1.450 377 E−01
Corrosion allowance
m
in.
mm
2.54* E+01
Corrosion rate
m/s
mil/yr
mm/a
2.54* E−02
(mpy)
Differential orifice
Pa
in. H2 O
kPa
2.488 4 E−01
pressure
(at 60°F)
cm H2 O
2.54* E+00
Gas-oil ratio
m3 /m3
scf/bbl
"standard"
1.801 175 E−01[1]
m3 /m3
Gas rate
m3 /s
scf/D
"standard"
2.863 640 E−02[1]
m3 /d
Geologic time
s
yr
Ma
Heat (fluid mechanics)
m
ft
m
3.048* E−01
cm
3.048* E+01
Heat exchange rate
W
Btu/hr
kW
2.930 711 E−04
kJ/h
1.055 056 E+00
Mobility
m2 /Pa•s
d/cp
µm2 /mPa•s
9.869 233 E−01
µm2 /Pa•s
9.869 233 E+02
Net pay thickness
m
ft
m
3.048* E−01
Oil rate
m3/s
bbl/D
m3/d
1.589 873 E−01
short ton/yr
mg/a
ta
9.071 847 E−01
Particle size
m
micron
µm
1.0*
Permeability-thickness
m3
md-ft
md•m
µm2 •m
3.008 142 E−04
Pipe diameter (actual)
m
in.
cm
2.54* E+00
mm
2.54* E+01
Pressure buildup
Pa
psi
kPa
6.894 757 E+00[2]
per cycle
Productivity index
m3 /Pa•s
bbl/(psi-D)
m3 (kPa•d)
2.305 916 E−02[2]
Pumping rate
m3 /s
U.S. gal/min
m3/h
2.271 247 E−01
L/s
6.309 020 E−02
Revolutions per minute
rad/s
rpm
rad/s
1.047 198 E−01
rad/m
6.283 185 E+00
Recovery/unit volume
m3 /m3
bbl/(acre-ft)
m3 /m3
1.288 931 E−04
(oil)
m3 /ha•m
1.288 931 E+00
Reservoir area
m2
sq mile
km2
2.589 988 E+00
acre
ha
4.046 856 E−01
Reservoir volume
m3
acre-ft
m3
1.233 482 E+03
ha•m
1.233 482 E−01
Specific productivity
m3 /Pa•s•m
bbl/(D-psi-ft)
m3 /(kPa•d•s)
7.565 341 E−02[2]
index
Surface or interfacial tension in reservoir capillaries
N/m
dyne/cm
mN/m
1.0* E+00
Torque
N•m
lbf-ft
N•m
1.355 818 E+00[3]
Velocity (fluid flow)
m/s
ft/s
m/s
3.048* E−01
Vessel diameter
m
1–100 cm
in.
cm
2.54* E+00
above 100 cm
ft
m
3.048* E−01
*An asterisk indicates the conversion factor is exact using the numbers shown; all subsequent numbers are zeros.
References
↑ 1.0 1.1 1.2 Since 1893, the U.S. basis of length measurement has been derived from metric standards. In 1959, a small refinement was made in the definition of the yard to resolve discrepancies both in this country and abroad, which changed its length from 3600/3937 m to 0.9144 m exactly. This resulted in the new value being shorter by two parts in a million. At the same time, it was decided that any data in feet derived from and published as a result of geodetic surveys within the U.S. would remain with the old standard (1 ft=1200/3937 m) until further decision. This foot is named the U.S. survey foot. As a result, all U.S. land measurements in U.S. customary units will relate to the meter by the old standard. All the conversion factors in these tables for units referenced to this footnote are based on the U.S. survey foot, rather than the international foot. Conversion factors for the land measure given below may be determined from the following relationships:
1 league=3 miles (exactly)
1 rod=16½ ft (exactly)
1 chain=66 ft (exactly)
1 section=1 sq mile
1 township=36 sq miles
↑ 2.0 2.1 2.2 2.3 2.4 2.5 This value was adopted in 1956. Some of the older International Tables use the value 1.055 04 E+03.
The exact conversion factor is 1.055 055 852 62* E+03
↑ 3.0 3.1 This sometimes is called the moment of inertia of a plane section about a specified axis.
↑ 4.0 4.1 4.2 The exact conversion factor is 1.638 706 4*E−05.
↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 Defined (not measured) value. (This reference should be ref 13)
↑ Not the same dimensions as “millidarcy-foot.”
↑ Not the same as reservoir “perm.”
↑ The exact conversion factor is 4.535 923 7*E−01.
↑ The exact conversion factor is 4.448 615 260 5*E+00.
↑ 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 Torque unit; see text discussion of “Torque and Bending Moment.”
↑ 11.0 11.1 11.2 Torque divided by length; see text discussion of “Torque and Bending Moment.”
↑ Defined (not measured) value.
See also
SI metric conversion factors
Nomenclature for SI metric conversion tables
Symbols in alphabetical order
Category