1 Gallon [liquid] to Ounces

1 gal = 128 fl oz

Calculation: fl oz = 1 gal × 128 = 128 fl oz

Gallon [liquid] to Ounce Converter

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How much is 1 gal?

3,785 mL (128 fl oz) equals about 3.79 liters, a large container volume.

1 gal on the ounce scale

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1 gal = 128.0 fl oz

Did you know? One US gallon is 3,785 mL.

1 US gallon = 3,785 mL = 128 fl oz. The Imperial (UK) gallon is larger at 4,546 mL.

How to Convert Gallon [liquid] to Ounce

1 gallon [liquid] = 128 ounces

Ounce = Gallon [liquid] × 128

Example: 1 gal × 128 = 128 fl oz

Reverse Conversion

To convert ounces back to gallons [liquid]:

  • Remember, 1 ounce equals 0.0078125 gallons [liquid].
  • To convert 128 fl oz to gal, multiply 128 x 0.0078125, resulting in 1 gal.

1 gal is also equal to:

Frequently Asked Questions

How much is 1 gallon [liquid] in ounces?

1 gallon [liquid] equals 128 ounces. This is calculated by multiplying 1 by the conversion factor 128.

What does 1 gallon [liquid] look like in ounces?

1 gallon [liquid] equals 128 ounces, a conversion commonly needed in cooking recipes, liquid measurements, and container sizing.

How do you calculate 1 gallon [liquid] to ounces?

Multiply 1 by the conversion factor 128. The calculation is 1 × 128 = 128 ounces. This factor is defined by international measurement standards.

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1 gallon [liquid] = 128 ounces
1 gallon [liquid] = 128 ounces — conversion chart

Nearby Conversions

0.5 gallons [liquid]64 ounces 1.5 gallons [liquid]192 ounces 2 gallons [liquid]256 ounces 2.5 gallons [liquid]320 ounces 3 gallons [liquid]384 ounces 3.5 gallons [liquid]448 ounces 4 gallons [liquid]512 ounces 4.5 gallons [liquid]576 ounces 5 gallons [liquid]640 ounces 5.5 gallons [liquid]704 ounces 6 gallons [liquid]768 ounces

For general conversions between gallons [liquid] and ounces, see the gallons [liquid] to ounces converter.

Conversion factors verified against NIST, BIPM, ISO 80000-3 1 US gallon = 3.785411784 L (exact, US customary). Last reviewed: March 2026
Adilson Fernandes By Adilson Fernandes
Tiago Fernandes Reviewed by Tiago Fernandes

All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.