Units of Measure
Introduction

The failure to convert units correctly can lead to a great deal of confusion. For example, 6 gallons (US) and 5 gallons (Imperial /UK) are both essentially equal to 22.7 liters. However, "22.7" has been rounded to "23" so often that many people believe that 6 US gallons equal 23 liters. Thus, many wine kits are labeled "6 gallons (23 liters)", and many carboys advertised as "23 liter" actually have a capacity of 6 gallons (22.7 liters), though some contain considerably more than 23 liters. "Six gallon kits" have been carefully designed to give the best results when they are made up to a volume close to 6 US gallons (22.7 liters), which should yield 30 bottles (750 ml x 30 = 22.5 liters) with very little waste. Using a carboy that contains 23 liters, or more, will waste and dilute kits, and may void your warranty.
Conversion of Commonly Used Units Relating to Volume & Weight
  • 25° C = 77° F

  • 1 Kg = 2.2046226 pounds
  • 1 US gallon = 3.7854118 liters
  • 1 UK gallon = 4.54609 liters

  • 5 UK gallons = 22.73 liters
  • 6 US gallons = 22.71 liters
  • 5 UK gallons = 6 US gallons within 0.1%

  • The density of purified water at 25° C rounded to 3 decimal places is:
    • 0.997 Kg/liter,
    • 2.198 lbs/liter,
    • 3.774 Kg/US gallon, or
    • 8.321 lbs/US gallon

  • 3 US gallons = 11.36 liters = 11.32 Kg or 24.96 lbs of purified water
  • 5 US gallons = 18.93 liters = 18.87 Kg or 41.60 lbs of purified water
  • 6 US gallons = 22.71 liters = 22.64 Kg or 49.93 lbs of purified water

  • 3 gallons US contains 15 bottles (750 ml) of wine + 110 ml
  • 5 gallons US contains 25 bottles (750 ml) of wine + 180 ml
  • 6 gallons US contains 30 bottles (750 ml) of wine + 160 ml
Conversion of Commonly Used Units Relating to Pressure
  • Atmospheric pressure under standard conditions at sea level =
    • 14.7 lbs/in2
    • 1013.25 millibars
    • 29.92 in high column of Hg
    • 76 cm high column of Hg
    • 34 foot column of water
    • 10.36 meter column of water

  • 1 bar = 14.5037738 pound-force/square inch (PSI)
Web Conversion of Other Units
The Internet offers a number of very convenient Web sites for converting just about anything. Click here for Online Conversion.