How much does a gallon of gasoline weigh? How much does a gallon of diesel weigh? These questions are important when you’re trying to decide what you should use for your car, tools, and equipment, or for your emergency power supply. And yes, we’ll be assuming that you’re interested in the weight of gasoline and not just any type of gas (e.g. oxygen).
So, the answer here is, of course, relative, as weight is contingent on other factors. But, to give you an average figure, a U.S. gallon of gasoline weighs about 6 pounds according to the Science and Technology Desk Reference. For comparison, a U.S. gallon of water weighs about 8.4 pounds.
To give you a clearer idea of how much does gas weigh and why, however, let’s go over the basic formula together.
The quality requirement of gasoline, as specified by ASTM D4052 (The Standard test method for density, relative density, and API gravity of liquids by Digital Density Meter), is indicated to be between 0.71 and 0.78 g/cm3 in a standard density measurement of 15°C (59°F).
So, if we use that 1 gallon equals 4 qts; 1 liter equals 1.1 qt, and 1000 ml equal 1 liter with a density of 0.78 g/mL (the maximum) we’ll come up to 2836 grams. And because 454g = 1 lb, this gives us a weight of 6.2 U.S. pounds for a gallon of gasoline. If we were to get a more average density than 0.78 g/mL we would’ve gotten exactly 6 pounds.
Another way to calculate it is by going through the Imperial gallon figure and converting it to U.S. gallons. So, if 1 Imperial gallon of water weight 10 pounds and we take a gasoline density of 0.73 g/mL this time, this means that one Imperial gallon of gasoline weighs 7.3 pounds. And since 1 U.S. gallon is equal to 0.83 Imperial gallons, we can simply multiply 7.3 by 0.83 and we’ll get the weight of a gallon of gasoline to be 6.059 pounds.
We can also look at the metric values. To do this we’ll have to start with the fact that 1 liter of water weighs 1 kilogram. If we factor in a specific gravity of 0.72 then if for U.S. Gallons we’ll get 3.78 liters and for Imperial gallons, we’ll get 4.54 liters. This is an easy calculation to make because the base relationship of the Imperial or Metric values is based on water with a specific gravity of 1. So, it’s easy to recall it as 1 Kg a liter or 10 pounds a gallon.
As for diesel, it has a density of roughly 0.832 g/cm^3 or 0.834 kg/LGallon of diesel can be calculated to have a mass of 6.943 pounds per gallon which is a bit heavier than gasoline.. So, a U.S. For the Imperial system, the number is 8.338 pounds per Imperial gallon.