Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
US gallons to Litres
Convert US gal to L instantly, then review the formula, assumptions, and rounding guidance.
VolumeInstant result
Decimals
Formula result = input × 3.785411784 ÷ 1. 1 US gal = 3.7854 L
Common examples
One value, several units
Litres3.7854 L
Millilitres3,785.4118 mL
Cubic metres0.0038 m³
Cubic centimetres3,785.4118 cm³
Imperial gallons0.8327 imp gal
US quarts4 qt
US cups16 cup
US fluid ounces128 fl oz
Conversion table
| US gal | L |
|---|---|
| 1 US gal | 3.7854 L |
| 2 US gal | 7.5708 L |
| 5 US gal | 18.9271 L |
| 10 US gal | 37.8541 L |
| 25 US gal | 94.6353 L |
| 50 US gal | 189.2706 L |
| 100 US gal | 378.5412 L |
Conversion chart
1 US gal3.7854 L
5 US gal18.9271 L
10 US gal37.8541 L
25 US gal94.6353 L
50 US gal189.2706 L
Worked example
1 litre equals 1,000 millilitres.
Unit definition
US gallons (US gal) One us gallons equals 3.785411784 litre.
Unit history
US gallons is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert US gal to litre.
3. Convert the base value to L and apply your display precision.
Understand the result before using it
US gallons to Litres converts a value measured in US gallons (US gal) into the equivalent value in Litres (L). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 3.785411784 ÷ 1
Assumptions
- US gallons and Litres represent the same volume quantity.
- The input is expressed in US gal; the output is expressed in L.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 US gal = 3.785411784 L. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a US gal measurement in a document that expects L.
- Compare a us gallons value with a value reported in litres.
- Check the US gal-to-L arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- US gallons and imperial gallons are different units; select the one your source actually uses.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert US gallons to Litres?
result = input × 3.785411784 ÷ 1 Using the displayed relationship, 1 US gal equals 3.785411784 L.
How many Litres are in one US gallons?
One US gallons is 3.785411784 Litres. The displayed digits may be rounded.
Can I reverse the US gal to L conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts L back to US gal.
Is the US gallons to Litres result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.