One
short ton of bituminous coal equals:
2,000
pounds
26,200,000 BTU of energy
4.52 barrels of crude oil
25,314 cubic feet of natural gas 
One
metric ton of crude oil equals:
2,204
pounds
7.46 barrels of domestic crude oil
6.99 barrels of foreign crude oil

To convert
Fahrenheit to Celsius: subtract 32, multiply by 5, and divide by 9.
To
convert Celsius to Fahrenheit: multiply by 9, divide by 5, and add 32.
The
radius of a one degree curve is 5730 feet. To find the radius of any curve,
divide this number by the number of degrees in the curve desired.
To
find a true bearing from any given magnetic, if the given bearing is NE
or SW, add the magnetic declination. If NW or SE, subtract.
CircleTangent
calculations for federal units:
5 acre spacing = 263’ circle radius
10 acre spacing = 372’ circle radius
20 acre spacing = 527’ circle radius
40 acre spacing = 745’ circle radius
80 acre spacing = 1053’ circle radius
160 acre spacing = 1489’ circle radius
320 acre spacing = 2106’ circle radius
640 acre spacing = 2979’ circle radius
Gas wells  include any 40 acre tract cut 50% or more by the circle. Oil
wells  include any 10 acre tract cut 50% or more.

1 Acre
= 43,560 square feet
1 Acre = 160 square rods
1 Acre = 1.1834 square arpents
1 Acre = 10 square chains
1 Acre = 160 square rods
1 Acre = 160 perches
1 Acre = 160 poles
1 Acre = .4047 hectare
1 Acre = 4047 square meters
1 Acre = is 208.708 feet square
1 Acre (Irish) = 1.6 English acres
1 Acre (Scottish) = 1.27 English acres
1 Acre Square = 5645.376 square varas or 75.136 varas x 75.136 varas
1 Are = 119.6 square yards or 100 centiares
Arpen measurements vary by locality:
1 Arpent (in LA, MS, AL, FL) = .84625 of an acre
1 Arpent Square (in LA, MS, AL, FL) = 191.994 feet or 2.909 chains on
each side
1 Arpent (AR and MO) = .8507 of an acre
1 Arpent Square (AR and MO) = 192.5 feet or 2.91667 chains on each side
1 Arpent = 10 perches (French)
1 Arshin = 1 Sazhen (Russian)
1 Arshin = 71 centimeters (Russian)
1 Arpent = 180 Pied (French)
1 Caballeria (TexasSpanish) = 108 acres
1 Centimeter = .3937 inches or .032808 feet
1 Chain = 66 feet
1 Chain = 4 rods
1 Chain = 4 perches
1 Chain = 4 poles
1 Chain = 100 links
1 Chain = 20.1168 meters
1 Chain = 23.76 varas
1 Colpa = 1 Irish acre
1 Cuerda (Puerto Rico) = .971 acre
1 Cuerda (Guatemala) = 35 varas
1 Fathom = 6 feet
1 Foot = 12 inches
1 Foot = .36 varas
1 Furlong = 660 feet
1 Furlong = 40 rods
1 Foot = 0.3048006 meter
1 Hectare = 10,000 square meters
1 Hectare = 2.471 acres or 100 ares
1 Hide (old English) = 120 acres, or amount of land to support 1 family
1 Inch = .0254 meter
1 Kilometer = 3280.83 feet
1 Kilometer = 1000 meters
1 Kilometer = .62 mile
1 Knot = 6080.2 feet
1 Labor (TexasSpanish)= 1,000,000 square varas or 1000 varas x 1000 varas
1 Labor = 177.136 acres
1 League = 3 miles or 84 arpents (French)
1 League (TexasSpanish) = 25,000,000 square varas
1 Lieue (League) = 3.1 miles or 84 arpents (French)
1 League = 4428.4 acres
1 Link = 7.92 inches
1 Link = .66 feet
1 Link = .2017 meter
1 Meter = 3.280833 feet
1 Meter = 39.37 inches
1 Meter Square = 10.764 square feet
1 Mile = 5,280 feet
1 Mile = 8 furlongs
1 Mile = 320 rods
1 Mile = 80 chains
1 Mile = 1.60935 kilometers
1 Mile = 320 perches
1 Mile = 320 poles
1 Mile = 8000 links
1 Mile = 1,609.2655 meters
1 Mile = 1900.8 varas
1 Mile Square = a regular Section of land
1 Mile Square = 27,878,400 square feet
1 Mile Square = 640 acres
1 Mile Square = 259 hectares
1 Mile Square = 2.59 square hectares
1 Morgen (German, Holland, S Africa) = about .6309 acres. Derived from
the German word Morgen ("morning"). The amount of land that
could be plowed in a morning.
1 Nautical Mile = 1013.4 fathoms
1 Out = 10 chains
1 Perch = 25 links
1 Perch = 1 pole
1 Perch = 1 rod
1 Perch = 16.5 feet
1 Perche = 18 Pied or 3 Toises (French)
1 Pied
1.066 feet (French)
1 Pole = 16.5 feet
1 Pole = 1 perch
1 Pole = 1 Rod
1 Pouce = 1/12th Pied or 12 linge (French)
1 Pueblo = A Spanish grant of less than 1000 acres
1 Rancho = A Spanish grant of more than 1000 acres
1 Rod = 1 pole
1 Rod = 1 perch
1 Rod = 16.5 feet
1 Rood = Unit of area usually equal to 1/4 acre
1 Sazhen = 2.134 meters (Russian)
1 Sazhen = 3 Arshin (Russian)
1 Section = 1 mile long, by 1 mile wide
1 Section = 640 acres
1 Sitio (TexasSpanish)= 1 league
1 Toise
6.396 feet or 6 Pied (French)
1 Township = 6 miles long, by 6 miles wide
1 Township = 36 sections
1 Township = 36 square miles
Vara Measurements differ by locality:
1 Vara (TexasSpanish) = 33 1/3 inches
1 Vara (Southern Colorado) = 32.993 inches
1 Vara (Florida) = 33.372 inches
1 Verst = 1.067 kilometers (Russian)
1 Verst = 500 Sazhen (Russian)
1 Virgate (old English)  1/4 of a Hide. The amount of land needed to
support a person.
1 Yard = 36 inches
1 Yard = 3 feet
1 Yard = 1.08 varas
1 Yard Square = 9 square feet

1 acrefoot
covers 1 acre of land 1 foot deep
1 acrefoot = 43,560 cubic feet = 325,900 gallons
1,000 gpm pumped continuously for 1 day produces 4.42 acrefeet
100 gpm pumped continuously for 1 year produces 160 acrefeet
1 cubic foot per send (cfs) = 449 gallons per minute (gpm)
