1 ft. (feet) = 12 in. (inches) = 0.3048 m (meter)
1 mile = 1760 yards = 5280 ft = 1.609km
1 nautical mile = 6080 ft. = 1852 m = 1.150782 mi
1 acre = 43,560 ft. = 0.4047 hectares
1 rev = 2PI radians = 360 degrees = 400 gradians
1 barrel = 31 IMP gal. = 31.5 US gal.
1 US gal. = 3.785 l = 4 quarts = 8 pints = 16 cups
1 liter (l) = 0.001 m3 = 2.1 pints (pt) = 1.06 quarts (qt) = 0.26 gallons (gal)
1 cup (c) = 0.2365882 l = 8 USoz
1 US oz = 8 US drams = 456.0129 drops = 480 US minim = 1.040842 IMP oz
1 N (newton) = 1 kg•m/s2 = 100,000 dyne
1 dyne = 2.248*10-6 lb. (pound)
1 kg = 9.81 N (on earth surface) = 2.2046 lb
1 oz. = 28.35 g (gram) = 0.2780N
1 imperial ton = 2000 lb = 907.2 kg
1 atm (metric atmos.) =760 mmHg at 0°C=14.223 lb/in2=1.0132*105 N/m2
1 psi = 2.0355 in. Hg at 32F = 2.0416 in. Hg at 62F = 6894.8 Pa
1 h.p. (horsepower) = 745.7 W (watts) = 2.545 BTU/hr. = 550 ft.lb./sec.
1 J (joule) = 1 N•m = 107 ergs = 0.2389 cal.
°F = [(°C*9)/5]+32, °C = Celsius (Centigrade), F = Fahrenheit
0.252 calories = 1 BTU (British Thermal Unit)
-273.2 °C = -459.7 °F = 0 K = 0 R = absolute zero
0 °C = 32 °F = 273.3 K = 491.7 R = Water Freezes
100°C = 212°F = 373.3 K = 671.7 R = Water Boils (1 atm. pressure)
π radians = 3.1416 radians = 180 degrees = 0.5 cycles
1 rpm (revolutions per minute) = 60 RPS (Revolutions per second) = 60Hz
1 fps (foot per second) = 1 ft/sec
1 mph (miles per hour) = 1 mi./hr.
1 cfm (cubic foot per minute) = 1 ft3/min.
1 year = 365 days = 52 weeks = 12 months
R = 1.987 cal/mole K = ideal gas law constant
K = Boltzmann’s constant = 1.3x10-16 erg/K = 1.3x10-23 J/K
h = Planck’s constant = 6.62x10-27 erg-sec = 6.62x10-34 J.sec
Avagadro’s number = 6.02x1023 atoms/atomic weight
electron charge = 1.60x10-19 coul.
electron rest mass = 9.11*10**-31 Kg
proton rest mass = 1.67*10**-27 Kg
speed of light (c) = 3.00x1010 cm/sec
speed of sound in dry air 25 C = 331 m/s
gravitational constant = 6.67*10**-11 Nm**2/Kg**2
permittivity of free space = 8.85*10**-12 farad/m
permeability of free space = 1.26*10**-6 henry/m
mean radius of earth = 6370 Km
mass of earth = 5.98*10**24 Kg
magnetic flux = weber (We) = 10**8 maxwell
magnetic flux density = tesla (T) = 10**4 gauss
magnetic intensity = ampere/m = 0.004*PI oersted
electric flux density = coulomb/m**2
1 flame = 4 foot candles = 43.05564 lux = 43.05564 meter-candles