Standard temperature is 60°F. Gasoline expands (weighs less per gallon) as it gets hotter.
Estimated Total Weight
61.50 lbs
27.90 kg
Volume in Liters
37.85 L
Density Applied
0.737 kg/L
Temp Adjustment
-0.4%
Formula Used: Weight = Volume × Density(adjusted for temp).
Standard gasoline weighs approximately 6.07 lbs per US Gallon at 60°F.
Figure 1: Comparison of calculated gasoline weight vs. water and diesel for the same volume.
Weight Reference Table (at Current Density)
Volume
Weight (lbs)
Weight (kg)
Weight (Metric Tonnes)
Table 1: Quick reference weights based on your selected fuel type and temperature.
What is Calculate the Weight of Gasoline?
To calculate the weight of gasoline is to determine the mass of a specific volume of fuel based on its density and temperature. Unlike solid objects, the weight of liquid fuel is not constant relative to its volume; it fluctuates significantly based on environmental factors. This calculation is a critical process in logistics, aviation flight planning, marine transport, and automotive racing, where every pound of weight impacts performance and safety.
Many individuals assume that "a gallon is a gallon," but in terms of mass, this is incorrect. A gallon of gasoline weighs significantly less than a gallon of water (approx. 6 lbs vs. 8.34 lbs). Understanding how to correctly calculate the weight of gasoline ensures that fuel tanks are not overfilled beyond weight limits and that transport vehicles remain within legal payload capacities.
Calculate the Weight of Gasoline Formula
The mathematical foundation to calculate the weight of gasoline relies on the relationship between Volume (V), Density ($\rho$), and Temperature (T). The core formula is:
Weight = Volume × Density
However, because gasoline expands when heated and contracts when cooled, a temperature correction factor must be applied for precision. The density of standard gasoline is often cited as 0.71 – 0.77 kg/L at 15°C (60°F).
Variables Explanation
Variable
Meaning
Unit
Typical Range
V
Volume of Fuel
Gallons / Liters
Any
$\rho$ (Rho)
Density
kg/L or lbs/gal
0.72 – 0.78 kg/L
T
Temperature
Fahrenheit (°F)
-20°F to 120°F
Coefficient
Expansion Rate
per degree C
~0.00095 / °C
Table 2: Key variables used to calculate the weight of gasoline.
Practical Examples
Example 1: The Boat Owner
A marina owner needs to calculate the weight of gasoline for a boat with a 100-gallon tank to ensure the boat lift can handle the load.
Input Volume: 100 US Gallons
Fuel Type: Regular Unleaded (approx 6.1 lbs/gal)
Temperature: 80°F (Hot summer day)
Calculation: At 80°F, gasoline is less dense. Instead of 6.1 lbs/gal, it might be 6.0 lbs/gal.
Result: 100 gal × 6.0 lbs = 600 lbs.
Example 2: Aviation Planning
A pilot needs to add 500 liters of Avgas. To calculate the weight of gasoline is a safety requirement for weight-and-balance.
Input Volume: 500 Liters
Density: 0.72 kg/L (Avgas)
Result: 500 × 0.72 = 360 kg (793 lbs).
How to Use This Calculator
Enter Volume: Input the total amount of fuel you possess or plan to purchase.
Select Unit: Choose between US Gallons, Imperial Gallons (UK), or Liters.
Choose Fuel Type: Select the grade (Regular, Premium, or Ethanol blends). Different chemical structures alter the density.
Input Temperature: Enter the ambient temperature of the fuel. Warmer fuel occupies more volume for the same weight, meaning density decreases.
Review Results: The calculator will instantly calculate the weight of gasoline in both pounds (lbs) and kilograms (kg).
Key Factors That Affect Gasoline Weight
When you calculate the weight of gasoline, consider these six financial and physical factors:
Temperature (Thermal Expansion): Gasoline has a high coefficient of thermal expansion. A truckload of 9,000 gallons loaded at 60°F will expand significantly at 90°F. If you buy by volume but sell by weight (or energy content), temperature matters financially.
Ethanol Content: Ethanol is denser than pure gasoline. E10 (10% ethanol) weighs slightly more per gallon than pure gas, while E85 weighs even more.
Specific Gravity: This is the ratio of the fuel's density to water. Variations in crude oil source can slightly alter specific gravity, affecting the final weight calculation.
Financial Cost of Weight: In logistics (trucking/shipping), every pound of fuel reduces the available payload for cargo. Accurately calculating fuel weight helps maximize revenue-generating cargo space.
Evaporation Loss: While not a direct weight factor, volatile components evaporate in heat, reducing total mass over time if not stored in a sealed system.
Grade/Octane Rating: Higher octane fuels often contain different additives (aromatics) which can lead to slight variations in density compared to regular unleaded fuel.
Frequently Asked Questions (FAQ)
Does temperature really change the weight of gasoline?
No, temperature changes the volume (density), not the total mass if the container is sealed. However, if you have a fixed 1-gallon container, the amount of mass that fits inside decreases as temperature rises.
What is the standard weight of a gallon of gas?
A standard US gallon of regular gasoline weighs approximately 6.073 pounds at 60°F (15°C).
Is diesel heavier than gasoline?
Yes, significantly. Diesel weighs approximately 7.0 lbs per US gallon, whereas gasoline weighs about 6.0 – 6.1 lbs per gallon.
How does Ethanol affect the calculation?
Ethanol is denser than gasoline but has less energy. E85 fuel will weigh more per gallon than regular E10 gasoline.
Why do I need to calculate the weight of gasoline for my car?
For daily driving, you usually don't. However, for towing, racing, or carrying heavy loads, knowing that a full 20-gallon tank adds ~120 lbs is useful for suspension tuning and GVWR limits.
Does the brand of gas change the weight?
Negligibly. While additive packages differ, the base density is regulated by standards (ASTM), so the weight difference between brands is minimal compared to temperature effects.
How accurate is this calculator?
This tool uses standard density averages. Actual density varies by batch and refinery. For certified aviation or trade applications, always use the specific gravity from the fuel bill of lading.
Is it better to buy gas in the morning?
Theoretically, yes, because the ground is cooler, making the gas denser (you get more mass per gallon). However, storage tanks are underground and insulated, so the actual difference is financially negligible for passenger cars.