Pounds to Gallons Conversion Calculator
Enter the weight in pounds below to calculate the volume in gallons.
Result: Gallons
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How to Convert Pounds to Gallons
Since pounds are a unit of mass and gallons are a unit of volume, which are different physical quantities, we need to know one more physical quantity of the ingredient or substance to convert between them. In this case, we need to account for the density of the substance whenever we do a conversion.
Therefore, to convert between pounds and gallons of an ingredient or substance, we must either multiply or divide by its density, depending on which direction we are performing the conversion.
Pounds to Gallons Formula
To convert a measurement in pounds to gallons, divide the weight by the density of the ingredient or material. Note that in order for this to work, the density must be in pounds per gallon (lb/gal).
If the density is given in grams per milliliter (g/mL), then first multiply the density by 8.3454 to convert to lb/gal.
For a density given in g/mL, you can use this simple formula to convert:
gallons = pounds / 8.3454 × density
Thus, the volume in gallons is equal to the weight in pounds divided by 8.3454 times the density (in g/mL) of the ingredient, substance, or material.
For example, let's calculate how many gallons are in a 20 lb tank of propane. Liquid propane has a density of 0.5081 g/mL.
gallons = 20 lb / 8.3454 × 0.5081 g/mL = 4.72 gal
Therefore, a full 20 lb tank of propane holds about 4.72 gallons.
Pound to Gallon Conversion Table
| Weight in Pounds: | Volume in Gallons of: | ||||
|---|---|---|---|---|---|
| Water | Milk | Cooking Oil | Gasoline | Diesel | |
| 1 lb | 0.12 gal | 0.116 gal | 0.136 gal | 0.162 gal | 0.141 gal |
| 2 lb | 0.24 gal | 0.233 gal | 0.272 gal | 0.324 gal | 0.282 gal |
| 3 lb | 0.359 gal | 0.349 gal | 0.408 gal | 0.486 gal | 0.423 gal |
| 4 lb | 0.479 gal | 0.465 gal | 0.545 gal | 0.648 gal | 0.564 gal |
| 5 lb | 0.599 gal | 0.582 gal | 0.681 gal | 0.81 gal | 0.705 gal |
| 6 lb | 0.719 gal | 0.698 gal | 0.817 gal | 0.972 gal | 0.846 gal |
| 7 lb | 0.839 gal | 0.814 gal | 0.953 gal | 1.133 gal | 0.987 gal |
| 8 lb | 0.959 gal | 0.931 gal | 1.089 gal | 1.295 gal | 1.128 gal |
| 9 lb | 1.078 gal | 1.047 gal | 1.225 gal | 1.457 gal | 1.269 gal |
| 10 lb | 1.198 gal | 1.163 gal | 1.362 gal | 1.619 gal | 1.41 gal |
| 11 lb | 1.318 gal | 1.28 gal | 1.498 gal | 1.781 gal | 1.551 gal |
| 12 lb | 1.438 gal | 1.396 gal | 1.634 gal | 1.943 gal | 1.692 gal |
| 13 lb | 1.558 gal | 1.512 gal | 1.77 gal | 2.105 gal | 1.833 gal |
| 14 lb | 1.678 gal | 1.629 gal | 1.906 gal | 2.267 gal | 1.974 gal |
| 15 lb | 1.797 gal | 1.745 gal | 2.042 gal | 2.429 gal | 2.115 gal |
| 16 lb | 1.917 gal | 1.861 gal | 2.179 gal | 2.591 gal | 2.256 gal |
| 17 lb | 2.037 gal | 1.978 gal | 2.315 gal | 2.753 gal | 2.397 gal |
| 18 lb | 2.157 gal | 2.094 gal | 2.451 gal | 2.915 gal | 2.538 gal |
| 19 lb | 2.277 gal | 2.21 gal | 2.587 gal | 3.077 gal | 2.678 gal |
| 20 lb | 2.397 gal | 2.327 gal | 2.723 gal | 3.239 gal | 2.819 gal |
When to Convert Pounds to Gallons
Pounds and gallons are both commonly used to measure cooking ingredients.
For cooking applications, most chefs suggest measuring dry ingredients by weight rather than volume to improve accuracy in the measurements.[1] The density of dry ingredients can vary for a variety of reasons, such as compaction and clumping.
The best way to ensure an accurate conversion is to use a scale. When a scale is not available, a calculator like the one above is a good way to estimate the weight to volume conversion.
Another useful application of weight and volume conversions is chemistry. When performing chemical reactions by combining separate chemicals to produce a new chemical, one must know the exact amount of each chemical to add in order to maximize the yield of the reaction.
It is common to mix powdered chemicals with liquid, or aqueous, chemicals, and this is where it becomes very useful to convert between weights and volumes.[2]
A third application of weight and volume conversions is when shipping freight when calculating the volumetric weight for cargo and packages. Trucks, ships, and airplanes are limited in the amount of weight or volume they can transport, so if one of those quantities is known, but the limitation is on the other, then it becomes necessary to convert between the two so as not to overload the shipping vehicle.
Keep reading to learn more about each unit of measure.
What Is a Pound?
Pounds are a widely used unit of weight in the United States. The National Bureau of Standards approved the international definition of the pound for use in the United States in 1959 after an agreement between six nations referred to as the International Yard and Pound Agreement.[3]
One pound is equal to 16 ounces, or 0.45359237 kilograms. In the avoirdupois or apothecaries' systems, one pound is equal to 7,000 grains.[4]
The pound is a US customary and imperial unit of mass. A pound is sometimes also referred to as a common ounce. Pounds can be abbreviated as lb (plural lbs), and are also sometimes abbreviated as lbm or #. For example, 1 pound can be written as 1 lb, 1 lbm, or 1 #, and 2 pounds can be written as 2 lbs.
A pound is frequently referred to as a unit of weight. While technically, a pound is a measure of mass, and weight is actually a measure of force, the two are equivalent as long as we are performing our calculations on Earth.
For example, an object with a mass of 1 pound weighs 1 pound on Earth, but only weighs one-sixth of that on the moon, yet still has the same mass.
Learn more about pounds.
What Is a Gallon?
The US liquid gallon is a unit of fluid volume equal to four quarts, eight pints, or sixteen cups.[5] The US liquid gallon should not be confused with the US dry gallon or the imperial gallon, which are different units of measure.
The gallon is a US customary unit of volume. Gallons can be abbreviated as gal; for example, 1 gallon can be written as 1 gal.
Learn more about gallons.
References
- National Institute of Standards & Technology, Culinary Measurement Tips, https://www.nist.gov/pml/owm/culinary-measurement-tips
- CK-12 Foundation, Introductory Chemistry (CK-12) - 12.6: Mass-Volume Stoichiometry, https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Introductory_Chemistry_(CK-12)/12%3A_Stoichiometry/12.06%3A_Mass-Volume_Stoichiometry
- National Bureau of Standards, Refinement of Values for the Yard and Pound, U.S. Department of Commerce, July 1, 1959, https://www.nist.gov/system/files/documents/2017/05/09/frn-59-5442-1959.pdf
- Encyclopædia Britannica, Avoirdupois weight, https://www.britannica.com/science/avoirdupois-weight
- National Institute of Standards and Technology, Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices, Handbook 44 - 2019 Edition, https://nvlpubs.nist.gov/nistpubs/hb/2019/NIST.HB.44-2019.pdf