 SYSTEMS OF UNITS -- THE BASICS
Units of measurement cannot be avoided in the practice of petrophysics, nor in our ordinary life. Different systems are used in different countries, in different industries, and even in different cultures in the same communities -- gets confusing. One of the best known and least used unit of measurement is the cubit. It is defined as the distance from the elbow to the tip of the longest finger. My personal cubit is right on 18 inches. Yours is probably different. Similarly, the English foot is slightly smaller than the French foot -- the respective Kings had different sized feet. To get around these problems, standards have been established and most countries except the USA have adopted them for personal, commercial, and scientific arenas.

This page covers most of what you need to survive in the oil and gas industry. Descriptions of Systeme Internatuinal or SI units, oilfield units, and conversions between them follow this introduction,

Some commonly used words that predate the SI units have different meanings in different parts of the world, and some abbreviations (for example the letter "M") have more than one meaning. Here is a ;list of the common problem words:

American           British/French/German    Prefix    Abbreviation     Factor
thousand            thousand                          Kilo       k                         10^3
million               million                              Mega    M                         10^6
billion                  milliard                            Giga      G                         10^9
trillion               billion                               Tera       T                         10^12
quadrillion           –                                    Peta       P                        10^15
quintillion         trillion                               Exa        E                         10^18
sextillion               –                                   Zetta      Z                          10^21
septillion          quadrillion                         Yolta     Y                          10^24

In many industries, the Roman numeral M, meaning 1000 and MM meaning 1 million were, and still are, widely used, not to be confused with the SI prefix M, meaning 1 million. Sometimes MM is shown in lower case as mm (for example mmcf/d, meaning 1 million cubic feet per day), not to be confused with the SI unit mm (millimeter). The SI prefix k, meaning 1000, is often written as a capital letter K, in keeping with the capitalization of many other prefixes for positive powers of 10 (for example M, G, T. etc).

There is no shortage of obsolete units of measurement, some still in wide use, such as nautical miles and knots in the ship and airline transportation. Some may be found in surveying, especially in non-English speaking countries. Here are some of the most common:

1 nautical mile = 1.1508 miles = 1/60 degree of latitude on Earth
1 knot = 1.1508 miles per hour
1 fathom = 6.0 feet = 1.829 meters
1 league = 5.556 km = 3.452 miles = 3 nautical miles
1 league (area) = 4.428 acres = 1.792 hectares

Some older survey plats may use these tems:
1 rod = 16.5 feet = 0.25 chains = 1 perch = 1 pole
1 chain = 4 rods = 20.17 meters = 66 feet = 100 links = 1/80 mile
1 furlong = 10 chains = 201.168 meters = 660 feet = 1/8 mile

These French measurements nay be found in Quebec an Louisiana and other early French settlements in the Americas.
1 pied = 1.0 French foot = 12.789 inches = 0.3248 meters = 1.0657 feet
1 loise = 6.0 pied = 1.949 meters = 6.394 feet
1 perche = 3 loise = 18.0 pieds = 5.847 meters = 19.183 feet
1 arpent = 10 perches = 30 loise = 180 pieds = 58.47 meters = 191.83 feet
1 arpent (area) = 3418.9 sq meters = 0.845 acres = 36 800 sq feet

Unfortunately, much of the work done in the oilfields uses a mixed set of units composed of British units (called English units in this Handbook) , CGS Units (an early form of metric units), and SI Units (called Metric units in this Handbook). Examples of English units are the foot, mile, and pound. Examples of Metric units are the meter, kilometer, and kilogram. Conversion back and forth between sets of units is a constant task for a petrophysicist.

A lengthy list of conversions is available at the bottom of this page. A useful freeware units conversion calculator can be downloaded HERE. This is an executable (.EXE) file and may be blocked by your security settings. INTERNATIONAL SYSTEM OF UNITS (SI)
SI units are widely used in scientific work. All the SI fundamental units and derived units are listed on this page, as well as the universal constants. Prefixes are applied to the SI names of units to indicate multipliers of the basic unit

SI Prefixes
Factor Name  Symbol
1024 yotta Y
1021 zetta Z
1018 exa E
1015 peta P
1012 tera T
109 giga G
106 mega M
103 kilo k
102 hecto h
101 deka da

Factor Name  Symbol
10-1 deci d
10-2 centi c
10-3 milli m
10-6 micro µ
10-9 nano n
10-12 pico p
10-15 femto f
10-18 atto a
10-21 zepto z
10-24 yocto y

LIST OF SI UNITS
UNIT SYMBOL DERIVATION BASE UNITS REPRESENTING
ampere A -- A electric current
becquerel Bq 1/s s-1 activity
candela cd -- cd luminous intensity
coulomb C A s A s charge
farad F A s/V kg-1 m-2 s4 A2 capacitance
gray Gy J/kg m2 s-2 absorbed dose
henry H V s/A kg m2 s-2 A-2 inductance
hertz Hz 1/s s-1 frequency
joule J N m kg m2 s-2 energy
kelvin [footnote 1] K -- K temperature
kilogram kg -- kg mass
lumen lm cd sr cd sr luminous flux
lux lx lm/m2 cd sr m-2 illumination
metre m -- m length
mole mol -- mol amount of substance
newton N kg m/s2 kg m s-2 force
ohm O [footnote 2] V/A kg m2 s-3 A-2 resistance
pascal Pa N/m2 kg m-1 s-2 pressure
radian rad -- rad plane angle
second s -- s time
siemens S 1/O kg-1 m-2 s3 A2 electric conductance
sievert Sv J/kg m2 s-2 dose equivalent
steradian sr -- sr solid angle
tesla T Wb/m2 kg s-2 A-1 magnetic flux density
volt V W/A kg m2 s-3 A-1 voltage
watt W J/s kg m2 s-3 power
weber Wb V s kg m2 s-2 A-1 magnetic flux
Non-SI unit approved for use with SI.
UNIT SYMBOL Value in SI Units
minute min 60 s
hour h 60 min = 3600 s
day d 24 h = 86 400 s
degree deg  (pi/180) rad
arcminute ', arcmin (1/60) deg = (pi/10 800) rad
arcsecond ", arcsec (1/60)' = (pi/648 000) rad
litre l, L [footnote 4] 1 dm3 = 10-3 m3
tonne t 103 kg
electronvolt eV (1.602 177 33 +- 0.000 000 49) x 10-19 J
unified atomic mass unit u (1.660 540 2 +- 0.000 001 0) x 10-27 kg
nautical mile -- 1852 m
knot -- 1 nautical mile per hour = (1852/3600) m/s
angstrom A [footnote 5] 10-10 m
are a 1 dam2 = 102 m2
hectare ha 104 m2
barn b 10-28 m2
bar bar 105 Pa
gal Gal 10-2 m/s2
curie Ci 3.7 x 1010 Bq
roentgen R 2.58 x 10-4 C/kg
rad rd, rad 10-2 Gy
rem rem UNIVERSAL CONSTANTS (SI Units)

 UNIVERSAL CONSTANTS CONSTANT SYMBOL VALUE and UNITS acceleration due to gravity g 9.806 65 m/s2 age of Universe t0 15(5) Gy atomic mass unit, unified u 931.494 32(28) MeV/c2 = 1.660 540 2(10) x 10-27 kg astronomical unit au 1.495 978 706 6(2) x 1011 m Avogadro constant NA 6.022 136 7(36) x 1023 mol-1 Bohr magneton muB 5.788 382 63(52) x 10-11 MeV/T Bohr radius aoo 0.529 177 249(24) x 10-10 m Boltzmann constant k 1.380 658(12) x 10-23 J/K = 8.617 385(73) x 10-5 eV/K cosmic background energy density rhogamma 4.647 7 x 10-34 (T/2.726 K)4 g/cm3 = 0.260 71 (T/2.726 K)4 eV/cm3 cosmic background number density ngamma 410.89 (T/2.726 K)3 cm-3 cosmic background temperature T0 2.726 +- 0.005 K critical density of Universe rhoc 2.775 366 27 x 1011 h02 MS Mpc-3 = 1.878 82(24) x 10-29 h02 g/cm3 = 1.053 94(13) x 10-5 h02 GeV/cm3 day, mean sidereal dsidereal 23h 56m 04s.090 53 deuteron (2H) mass md 1875.613 39(57) MeV/c2 Earth mass ME 5.973 70(76) x 1024 kg Earth radius (equatorial) RE 6.378 140 x 106 m electron charge magnitude e 1.602 177 33(49) x 10-19 C = 4.803 206 8(15) x 10-10 esu electron mass me 0.510 999 06(15) MeV/c2 = 9.109 389 7(54) x 10-31 kg electron radius, classical re 2.817 940 92(38) x 10-15 m electron Compton wavelength lambdabare 3.861 593 23(35) x 10-13 m entropy density/Boltzmann constant s/k 2.892 4 (T/2.726 K)3 cm-3 fine structure constant alpha 1/137.035 989 5(61) gravitational constant GN 6.672 59(85) x 10-11 m3/(kg s2) = 6.707 11(86) x 10-39 h c/(GeV/c2)2 Hubble constant H0 100 h0 km/(s Mpc) = h0/9.778 13 Gy Hubble constant, normalized h0 0.5 < h0 < 0.85 jansky Jy 10-26 W/(m2 Hz) light year (deprecated) ly 0.306 6... pc = 0.946 1... x 1016 m Naperian (natural) logarithm base e 2.718 281 828 459 045 235 nuclear magneton muN 3.152 451 66(28) x 10-14 MeV/T parsec (au/arcsec) pc 3.085 677 580 7(4) x 1016 m = 3.262... ly permeability of free space mu0 4 pi x 10-7 N/A2 = 12.566 370 614... x 10-7 N/A2 permittivity of free space epsilon0 8.854 187 817... x 10-12 F/m pi pi 3.141 592 653 589 793 238 Planck constant h 6.626 075 5(40) x 10-34 J s Planck constant, reduced hbar 1.054 572 66(63) x 10-34 J s = 6.582 122 0(20) x 10-22 MeV s Planck mass mP 1.221 047(79) x 1019 GeV/c2 = 2.176 71(14) x 10-8 kg proton (1H) mass mp 938.272 31(28) MeV/c2 = 1.672 623 1(10) x 10-27 kg = 1.007 276 470(12) u = 1836.152 701(37) me Rydberg energy h c Roo 13.605 698 1(40) eV Schwarzschild radius of Sun 2 GN MS/c2 2.953 250 08 km speed of light in vacuum c 299 792 458 m/s Stefan-Boltzmann constant sigma 5.670 51(19) x 10-8 W/(m2 K4) strong coupling constant alphas 0.118(3) Sun distance from Core Ro 8.0(5) kpc Sun luminosity LS 3.846 x 1026 W Sun mass MS 1.988 92(25) x 1030 kg Sun radius (equatorial) RS 6.96 x 108 m Sun speed around Core Thetao 220(20) km/s Sun speed to cosmic background 369.5 +- 3.0 km/s Thompson cross section sigmaT 0.665 246 16(18) barn W+- boson mass mW 80.33(15) GeV/c2 Wien displacement law constant b 2.897 756(24) x 19) x 10-3 m K year, sidereal (fixed star to fixed star, 1994) ysidereal 31 558 149.8 s year, tropical (equinox to equinox, 1994) y 31 556 925.2 s Z0 boson mass mZ 91.187(7) GeV/c2 OILFIELD UNITS CONVERSION TABLE
 OILFIELD UNITS CONVERSION TABLE Original Unit Multiplied By Conversion Factor Equals Final Unit A acres x 0.404 69 = hectares acres x 43,560 = square feet (ft2) acres x 4,046.873 = square meters (m2) acre-feet x 43,560 = cubic feet (ft3 or cf) acre-feet x 7,758 = barrels angstrom units x 1.0E-10 = meters (m) atmospheres x 14.70 = pounds/square inch atmospheres x 1.033 = kilograms/square centimeter atmospheres x 1.013250E+05 = pascal atmospheres x 33.90 = Feet of water atmospheres x 76.0 = centimeter of mercury B barrels (crude oil) x 5.6146 = cubic feet of crude oil barrels (crude oil) x 0.158 987 3 = cubic meters of crude oil barrels (crude oil) x 42 = US gallons of crude oil, US barrels (crude oil) x 158.987 3 = liters of crude oil barrels (crude oil) x 0.136 = metric tons of crude oil barrels/day x 0.0292 = Gallons(US)/minute barrels/day x 1.84 = cubic centimeters/second barrels (crude oil) x 0.15 = short tons of crude oil barrels, US liquid x 0.75 = barrels of crude oil barrels, US liquid x 31.5 = gallons, US bars x 0.98 = atmospheres bars x 14.50 = pounds/square inch British thermal units (Btu) x 3.931E-04 = horsepower-hours British thermal units (Btu) x 0.000 292 8 = kilowatthours (kWh) bushels, US x 0.035 239 07 = cubic meters (m3) C calories (cal) x 4.186 8 = joules (J) centimeters (cm) x 0.394 = inches (in) centimeters of mercury x 0.44 = feet of water centimeters/second x 0.036 = kilometers/hour centipoise x 0.01 = poise centipoise x 0.01 = grams/cm-sec centipoise x 0.0010 = pascal-second centipoise x 6.72E-04 = pounds/ft-sec cubic centimeters (cm3) x 3.531E-05 = cubic feet (ft3 or cf) cubic centimeters (cm3) x 0.06102 = cubic inches (in3) cubic centimeters (cm3) x 2.642E-04 = gallons, US liquid cubic centimeters (cm3) x 1.0E-03 = liters (L) cubic feet (ft3 or cf) x 28,320 = cubic centimeters (cm3) cubic feet (ft3 or cf) x 1728 = cubic inches (in3) cubic feet (ft3 or cf) x 7.48 = gallons, US liquid cubic feet (ft3 or cf) x 28.316 8 = liters (L) cubic feet (ft3 or cf) x 2.831685E-02 = cubic meters cubic feet/minute x 472 = cubic centimeters/second cubic feet/minute x 4.72E-4 = cubic meters/second cubic feet/minute x 0.12 = gallons/second cubic feet/minute x 0.471 947 4 = liters/second cubic inches (in3) x 16.38706 = cubic centimeters (cm3) cubic inches (in3) x 1.639E-05 = cubic meters (m3) cubic inches (in3) x 4.329E-03 = gallons (gal) cubic inches (in3) x 0.016387 06 = liters (L) cubic meters (m3) x 35.315 = cubic feet (ft3 or cf) cubic meters (m3) x 264.20 = gallons, US liquid cubic meters (m3) x 1,000 = liters (L) cubic meters/sec (m3/s) x 15,850 = gallons/minute cubic meters/sec (m3/s) x 2118 = cubic feet/minute cubic meters/sec (m3/s) x 60,000 = liters/minute cycles/second x 1.0 = hertz D darcy x 0.9869E-12 = meter squared days (mean solar) x 86,400 = seconds degrees (angle) x 0.0111 = quadrants degrees (angle) x 0.017 453 29 = radians degrees (angle) x 3,600 = seconds degrees/second x 0.16667 = revolutions/minute dynes x 1.0E-05 = joules/meter (newtons) dynes/square centimeter x 1.0E-06 = bars E em (pica) x 0.42 = centimeters (cm) ergs x 1.0E-07 = joules (J) ergs x 2.78E-14 = kilowatthours (kWh) ergs/second x 1.3E-10 = horsepower (hp) ergs/second x 1.0E-10 = kilowatts F feet (ft) x 30.48 = centimeters (cm) feet (ft) x 12 = inches (in) feet (ft) x 0.3048 = meters (m) feet (ft) x 1.645E-04 = miles (nautical) feet (ft) x 1.894E-04 = miles (statute) feet of water x 0.029499 = atmospheres of water feet of water x 0.8826 = inches of mercury feet of water x 0.433515 = pounds/square inch feet/minute x 0.5080 = centimeter/second feet/second x 1.09728 = kilometers/hour feet/second x 0.59248 = knots feet/second x 0.681818 = miles/hour foot-candles x 10.763 91 = lumens/square meter foot-pounds x 3.77E-07 = kilowatthours (kWh) foot-pounds/minute x 2.26E-05 = kilowatts (kW) foot-pounds/sec x 0.00181 = horsepower G gallons, US (gal) x 0.031 75 = barrels gallons, US (gal) x 0.02381 = barrels of crude oil gallons, US (gal) x 3,785.41 = cubic centimeters (cm3) gallons, US (gal) x 0.1337 = cubic feet (ft3 or cf) gallons, US (gal) x 3.785412E-03 = cubic meters (m3) gallons, US (gal) x 0.832675 = gallons, imperial gallons, US (gal) x 3.785412 = liters (L) gallons, liquid British imperial x 1.2014 = gallons, US liquid gallons of crude oil x 0.02380952 = barrels of crude oil gallons/minute, US x 8.0208 = cubic feet/hour gallons/minute, US x 0.134 = cubic feet/minute gallons/minute, US x 6.309E-05 = cubic meters/sec gausses x 1.0E-04 = webers/square meter grains x 0.064798 91 = grams (g) grams (g) x 0.0353 = ounces grams (g) x 2.204623E-03 = pounds (lb) grams/centimeter x 5.6E-03 = pounds/inch grams/cubic centimeter x 62.43 = pounds/cubic foot grams/cubic centimeter x 8.347 = pounds/gallon grams/liter x 1,000 = parts/million grams/liter x 8.34 = pounds/1,000 gallons grams/liter x 0.06243 = pounds/cubic foot grams/square centimeter x 2.04816 = pounds/square foot gram-calories x 1.56E-06 = horsepower-hours gram-calories x 1.16E-06 = kilowatthours (kWh) H hectares (ha) x 2.471 = acres hectares (ha) x 107,600 = square feet (ft2) hectares (ha) x 10,000 = square meters (m2) horsepower (hp) x 1.014 = horsepower (metric) horsepower (hp) x 42.44 = British thermal units/minute horsepower (hp) x 550 = foot-pounds/second horsepower-hour (hp-hr) x 2.684520E+6 = Joules horsepower (hp) x 0.746043 = kilowatts horsepower (metric) x 0.986 = horsepower horsepower (metric) x 542.5 = foot-pounds/second I inches (in) x 2.54 = centimeters (cm) inches (in) x 0.0254 = meters (m) inches (in) x 1.578E-05 = miles (mi) inches of mercury x 0.4912 = pounds/square inch inches of water at (4oC) x 2.458E-03 = atmospheres inches of water at (4oC) x 0.03 = pounds/square inch J joules (J) x 9.48E-04 = British thermal units (Btu) joules (J) x 2.778E-04 = watthours (Wh) K kilograms (kg) x 2.204 6 = pounds (lb) kilograms (kg) x 9.84E-04 = tons, long kilograms (kg) x 1.1E-03 = tons, metric (t) kilograms/sqhare meter x 1.42E-03 = pounds/square inch kilograms/meter x 0.67197 = pounds/foot kilograms/square centimeter x 0.9678 = atmospheres kilograms/square centimeter x 14.223 = pounds/square inch kilograms/square meter x 9.81E-05 = bars kilogram-meters x 2.72E-06 = kilowatthours (kWh) kilometers (km) x 3,280.84 = feet (ft) kilometers (km) x 0.621 4 = miles (mi) kilometers/hour x 0.91134 = feet/second kilometers/hour x 0.53995 = knots kilometers/hour x 0.62137 = miles/hour kilowatts (kW) x 1.341 = horsepower (hp) kilowatts (kW) x 1,000 = watts (W) kilowatthours (kWh) x 3,413 = British thermal units (Btu) kilowatthours (kWh) x 3.60E+06 = Joules L liters (L) x 0.0063 = barrels of oil liters (L) x 0.0084 = barrels liters (L) x 0.035315 = cubic feet (ft3 or cf) liters (L) x 61.02 = cubic inches (in3) liters (L) x 0.264 = gallons long tons x 1,016.047 = kilograms (kg) long tons x 1.016047 = metric tons (t) long tons x 2,240 = pounds (lb) long tons x 1.12 = short tons (st) M meters (m) x 3.281 = feet (ft) meters (m) x 6.21E-04 = miles (statute) meters/second x 2.23 = miles/hour meters/second x 196.8 = feet/minute metric tons (t) x 1,000 = kilograms (kg) metric tons (t) x 2,204.62 = pounds (lb) metric tons (t) x 1.1023 = short tons (st) metric tons of crude oil x 7.33 = barrels (bbl) microns x 1.0E-06 = meters (m) miles, statute x 161,000 = centimeters (cm) miles, statute x 5,280 = feet (ft) miles, statute x 1.609344 = kilometers (km) miles, statute x 1,609 = meters (m) miles, statute x 0.868975 = miles, nautical miles/hour x 44.70 = centimeter/second miles/hour x 1.4667 = feet/second meters (m) x 3.281 = feet meters (m) x 6.21E-04 = miles (statute) millimeters x 0.03937 = inches milligrams/liter x 1 = parts/million million gallons/day x 1.5472 = cubic feet/second minutes (angles) x 0.0167 = degrees N newtons x 0.22481 = pounds force newtons x 100,000 = dynes O ounces (oz) x 28.34 = grams (g) ounces (oz) x 0.0625 = pounds (lb) P pascal x 1 = newton/sq meter pascal x 9.871E-06 = atmosphere parts/million x 8.34 = pounds/million gallon (gal) pints, US liquid x 0.125 = gallons, US (gal) poise (P) x 1 = grams/centimeter second poundals x 13,826 = dynes pounds (lb) x 4.45E+05 = dynes pounds (lb) x 453.59 = grams (g) pounds (lb) x 4.5359E-04 = Tons (metric) pounds (lb) x 4.448 = joules/meter (newtons) pounds (lb) x 0.45359237 = kilograms (kg) pounds (lb) x 16 = ounces (oz) pounds of water x 27.68 = cubic inches (in3) pounds of water x 0.11983 = gallons (gal) pounds/cubic foot x 0.1337 = pounds/gallon (US) pounds/cubic foot x 0.006944 = pounds/sq inch/foot (psi/ft) pounds/cubic foot x 0.016026 = specific gravity pounds/cubic foot x 0.016026 = grams/cubic centimeter pounds/cubic foot x 16.026 = kilograms/cubic meter pounds/cubic inch x 27.68 = grams/cubic centimeter pounds/cubic inch x 27,680 = kilograms/cubic meter pounds/foot x 1.4882 = kilograms/meter pounds/inch x 178.60 = grams/centimeter pounds/gallon (ppg) x 0.12005 = specific gravity pounds/gallon (ppg) x 0.052 = pounds/sq inch/foot (psi/ft) pounds/gallon (ppg) x 7.48 = pounds/cubic foot pounds/gallon (ppg) x 0.1198 = grams/cubic centimeter pounds/square inch x 0.0680 = atmospheres pounds/square inch x 2.3095 = feet of water pounds/square inch x 2.03602 = inches of mercury pounds/square inch x 703.0696 = kilograms/square meter pounds/square inch x 6.894757E+03 = pascal pounds/square inch x 144 = pounds/square foot pounds/sq inch/foot(psi/ft) x 19.23 = pounds/gallon (US) pounds/sq inch/foot(psi/ft) x 144 = pounds/cubic foot pounds/sq inch/foot (psi/ft) x 2.3095 = specific gravity Q quadrants, angle x 90 = degrees quadrants, angle x 1.5708 = radians quarts, liquid x 57.75 = cubic inches (in3) quarts, liquid x 9.46E-04 = cubic meters (m3) R radians x 57.29 = degrees radians x 3,438 = minutes radians x 206,000 = seconds revolutions x 360 = degrees revolutions x 4 = quadrants revolutions x 6.283185 = radians S seconds (angle) x 2.78E-04 = degrees seconds (angle) x 4.848137E-06 = radians short tons (st) x 0.8929 = long tons short tons (st) x 0.9071847 = metric tons (t) short tons (st) x 2,000 = pounds (lb) short tons of crude oil x 6.65 = barrels (bbl) specific gravity x 1 = grams/cubic centimeter specific gravity x 0.433 = pounds/sq inch/foot (psi/ft) specific gravity x 8.33 = pounds/gallon (US) specific gravity x 350.5 = pounds/barrel specific gravity x 62.4 = pounds/cubic foot square centimeters (cm2) x 1.08E-03 = square feet (ft2) square centimeters (cm2) x 0.1550 = square inches (in2) square inch (in2) x 6.4516 = square centimeter square feet (ft2) x 2.2956E-05 = acres square feet (ft2) x 929.03 = square centimeters (cm2) square feet (ft2) x 144 = square inches (in2) square feet (ft2) x 0.09290304 = square meters (m2) square feet (ft2) x 3.59E-08 = square miles (mi2) square kilometers (km2) x 247.10 = acres square kilometers (km2) x 100 = hectares square kilometers (km2) x 0.386 = square miles (mi2) square meters (m2) x 2.471E-04 = acres square meters (m2) x 10.763915 = square feet (ft2) square meters (m2) x 3.86E-07 = square miles (mi2) square miles (mi2) x 640 = acres square miles (mi2) x 27,900,000 = square feet (ft2) square miles (mi2) x 2.589988 = square kilometers (km2) T therms x 100,000 = BTUs of natural gas therms x 1.054804E+08 = joules (J) tonnes x 1.0 = tons, metric tons, long x 1,016.047 = kilograms (kg) tons, long x 1.016047 = metric tons (t) tons, long x 2,240 = pounds (lb) tons, long x 1.12 = short tons (st) tons, metric (t) x 7.33 = barrels of crude oil tons, metric (t) x 1,000 = kilograms (kg) tons, metric (t) x 2,204.62 = pounds (lb) tons, short (st) x 6.65 = barrels of crude oil tons, short (st) x 0.8929 = long tons tons, short (st) x 0.9071847 = metric tons (t) tons, short (st) x 2,000 = pounds (lb) W watts (W) x 3.41219 = British thermal units/hour watts (W) x 0.001341 = horsepower (hp) watts (absolute) x 1 = joules/second watthours (Wh) x 3.41219 = British thermal units (Btu) watthours (Wh) x 2,656 = foot-pounds weeks x 168 = hours Y years (mean of 4-year period) x 365.25 = days years (mean of 4-year period) x 8,766 = hours years (mean of 4-year period) x 526,000 = minutes (time) years (mean of 4-year period) x 31,558,150 = seconds (time) years (mean of 4-year period) x 52.17 = week
Page Views ---- Since 01 Jan 2015
Copyright 1978 - 2018 E. R. Crain, P.Eng. All Rights Reserved