🧪 Gallons ⇄ Liters Volume Converter

Convert volume between US gallons and liters in a single step. This converter is useful for fuel, water, chemical tanks, recipes, brewing, and any situation where US and metric volumes meet.

Gallons and liters conversion results

Enter a volume and choose whether it's in gallons or liters, then select Convert Gallons ⇄ Liters to see both units.

Volume conversion breakdown

After you run a conversion, this section shows the starting value, the direction of conversion, and the exact factors used so you can document or verify the math.

Volume converter inputs and key terms

This converter focuses on US gallons and liters, which are two of the most common volume units for liquids. Here's what each input means.

• Volume value: The numeric size of the volume you want to convert. This might come from a tank label, a recipe, a specification sheet, or a utility bill.
• Starting unit: Whether your original number is expressed in US gallons or in liters. The converter uses this to determine which direction to convert.
• US gallon (gal): A US customary unit of volume commonly used for fuel, water, and other liquids in the United States. One US gallon is defined as exactly 3.785411784 liters.
• Liter (L): The standard metric unit of volume used worldwide. One liter is equal to 1 cubic decimeter, or 0.001 cubic meters.
• Conversion factor (gal → L): One US gallon is exactly 3.785411784 liters. Multiplying by this factor converts gallons to liters.
• Conversion factor (L → gal): One liter is approximately 0.264172052 US gallons. Multiplying by this factor converts liters to gallons.
• US vs imperial gallons: This calculator uses US gallons only. Imperial gallons used in some countries are larger and would require a different factor.

Formulas used in the Gallons ⇄ Liters Converter

The US gallon–liter relationship is defined precisely, so the calculations are straightforward multiplications by fixed constants.

1. Converting US gallons to liters

Let:
Vgal = volume in US gallons
VL = volume in liters
kgal→L = conversion factor from gallons to liters
Using the standard:
kgal→L = 3.785411784
Then:
VL = Vgal × kgal→L

2. Converting liters to US gallons

Let:
VL = volume in liters
Vgal = volume in US gallons
kL→gal = conversion factor from liters to gallons
Because:
1 gal = 3.785411784 L,
we have:
kL→gal = 1 ÷ 3.785411784 ≈ 0.264172052
Then:
Vgal = VL × kL→gal

The calculator keeps a precise internal factor, then rounds the displayed result to a few decimal places for clarity. This is adequate for most planning, estimating, and comparison tasks.

Gallons ⇄ Liters Converter FAQs

• What's the difference between US gallons and imperial gallons?
  US gallons are smaller than imperial gallons. One imperial gallon is about 4.54609 liters, compared with 3.78541 liters for a US gallon. This calculator uses US gallons only, which are standard in the United States for fuel, water, and many consumer products.
• How accurate are these gallon-to-liter conversions?
  The US gallon–liter relationship is defined exactly, so the math is precise. The only approximation comes from rounding the displayed result to a practical number of decimal places. For almost all real-world uses, this level of precision is more than sufficient.
• Can I use this converter for fuel economy calculations?
  Yes. Converting tank sizes and fuel volumes between gallons and liters is common when comparing vehicles or fuel consumption in different countries. Just remember that fuel economy also depends on distance units (miles vs kilometers), which are handled by separate converters.
• Is this converter suitable for chemical or lab work?
  For many practical lab and industrial uses, yes. However, critical processes may require volume measurements in milliliters or cubic meters with tight tolerances. In those cases, you'll still use the same conversion factors, but you may want to carry more significant digits than what's shown here.
• How should I round volume conversions when ordering liquids?
  It's common to round up slightly to ensure you have enough product, especially for paints, coatings, cleaning agents, or process liquids. Your supplier or manufacturer may also recommend a specific safety margin depending on the application.
• Can I convert between liters and cubic meters with this tool?
  Indirectly, yes, because 1 cubic meter (m³) equals 1,000 liters. You can convert gallons to liters here, then divide liters by 1,000 to get cubic meters—or multiply cubic meters by 1,000 to get liters first and then convert to gallons.