Sometimes, understanding a volume measurement is simpler if it's visualized in a way that’s more familiar. Liters may be difficult to picture, whereas converting the volume into gallons gives a more concrete term. The United States uses two different gallon measurements  wet for water and fluids, and dry for goods such as corn, wheat or other solid materials. In addition, the United Kingdom uses another type of measurement: imperial gallons. Any of the three volume measurements may be converted to or from liters.
Things You'll Need
 Calculator

Convert a volume expressed in liters as its equivalent expressed in U.S. wet gallons. Multiply the number of liters by a conversion factor of 0.264172052 using a calculator. For example, if you have 15 liters of liquid, multiply that number by 0.264172052. You should arrive at 3.96258078. You can also convert a U.S. wet gallon measurement to liters by applying a conversion factor of 3.78541179. So, our 3.96258078 wet gallons becomes 15 liters when multiplied by the wet gallon to liter conversion factor.

Convert a liter volume to U.S. dry gallons by multiplying the number of known liters by a conversion factor of 0.22702074. In this case, 15 liters of a dry good such as rice becomes 3.4053111 U.S. dry gallons. Convert back to liters by applying the appropriate conversion factor. For example, 3.4053111 U.S. dry gallons multiplied by a conversion factor of 4.40488380 becomes 15 liters.

Convert the number of liters to imperial gallons using a conversion factor of 0.21996925. The same 15 liters of dry or wet material multiplied by a liter to imperial gallon conversion factor of 0.21996925 is 3.29953875 imperial gallons. The calculation for imperial gallons to liters uses a conversion factor of 4.54608990. So, multiplying 3.29953875 imperial gallons by that conversion factor results in a volume of 15 liters.
Tips & Warnings
 You may need to either carry the decimal place out further, or truncate the number of decimal places to one or two depending on the accuracy of the results you need. The website listed in the Resources section of this article provides conversion factors that include more decimal places. Round any of the results down to fewer decimal places after making the conversion.
References
 Photo Credit Hyrma/iStock/Getty Images