Conversion Factors
To convert temperature  Into  Multiply by
°F °C 0.556°C -17.8
°F °F 1.8°C +32
°C °K 1.0°C +273
Lenght    
mils microns 25.4
mils millimeters 0.0254
inches mils 1000 
inches centimeters 2.54
feet meters 0.3048
miles feet 5280
yards feet 3
Mass    
ounces grams 28.4
pounds kilograms 0.45
grams  ounces (troy) 0.03215
tons pounds 2000
Area    
square inches square centimeters 6.5
square feet square meters 0.09
square yards square meters 0.8
square miles square kilometers 2.6
acres hectares 0.4
Volume    
teaspoons millimeters 5
tablespoons millimeters 15
fluid ounces millimeters 30
quarts liters 0.95
gallons liters 3.8
cubic feet cubic meters 0.03
cubic yards cubic meters 0.76
Universal Gas Constant R=0.0821 (Atm) (I)/(°K) (mole)  
Acceleration Due to Gravity g=32.17ft/sec² 9.8m/sec²  
Avogrado’s Constant N=6.023×10²³molecules/mole  
Speed of Light c=186,000 miles/sec, 3×10¹° cm/sec  
Heat of Fusion (water 1atm, 0°C) Hf=79.7 cal/g  
Heat of Vaporization (water 1atm, 100°C) Hv=540 cal/g  
Volume of Perfect Gas 22.4l at 0°C, 760 torr  
Faraday’s Constant F=96.494 coulombs/equiv.weight  
Planck’s Constant h=6.626×10 (-27) erg/sec  
Bragg’s Law n=2d sin  
Absolute Zero -273.15°C  
Temperature of Liquid Nitrogen -195.8°C