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Conversion Factors

CONVERSION FACTORS: 

Length
1 mi = 5,280 ft = 1.609 km
1 km = 0.6214 mi = 3,281 ft

Area
1 sq mi = 640 acres = 2.590 sq km
1 acre = 43,560 sq ft = 4,047 sq m

Volume
1 AF = 325,872 gal = 1,233 cu m
1 AF = 43,560 cu ft = 1,613 cu yd
1 cfs-day = 1.983 AF
1 cubic foot = 7.48 gallons = 0.0283 cubic meters
1 cfs-day = 1.983 AF
1 cubic meter = 35.51 cubic feet

Discharge Rate
1 cu m/sec = 15,850 gpm = 70.04 acre-ft/day
1 cfs = 2,228 gpm = 0.646317 mgd = 1.983 AF/day
1 AF/day = 226.3 gpm = 0.5042 cfs
1 gpm = 8.0208 cu ft/hr
1 cubic foot per second
     (cfs) = 448.83 gallons per minute
     (gpm) = 0.646 million gallons per day
     (mgd) = 0.0283 cubic meters per second (cms)

Energy
1 kilowatt –hour (kWh) = 3,413 BTU [i]
1 kilowatt (kW) = 1,000 watts
                      = 1.341 horsepower
                      = 56.88 BTU/minute
                      = 737.56 ft-lbs/second
 
1 megawatt (MW) = 1,000 kilowatts
                         = 1 million watts
1 gigawatt (gW)   = 1,000 megawatts
 
Energy Equivalents
1 barrel of oil (42 gallons)
    = 470 kWh at 27% efficiency [i]
   = 520 kWh at 30 % efficiency
   = 660 kWh at 38% efficiency [iii]
1 ton of coal = 2,500 kWh at 37% efficiency [iv]
1,000 cubic feet of natural gas = 59 kWh at 27% efficiency [ii]
                                          = 83 kWh at 38% efficiency [iii]


[i] 1 BTU (British Thermal Unit) is the amount of energy required to raise the temperature of one pound of water one degree Fahrenheit.
[ii] Typical efficiency for a combustion turbine.
[iii] Typical efficiency for new oil- or gas-fired base load steam plant or combined cycle plant.
[iv] Typical efficiency for a new base load coal-fired steam plant.