Direct conversion
Convert gallon (US) [gal US] to fluid ounce (UK) [fl oz UK] instantly with formula, examples, chart, and FAQs.
1 gallon (US) [gal US] = 133.22787 fluid ounce (UK) [fl oz UK]
1 gallon (US) [gal US] = 133.22787 fluid ounce (UK) [fl oz UK]
Example: 1 gallon (US) [gal US] equals 133.22787 fluid ounce (UK) [fl oz UK].
Volume conversions use cubic metre as the reference unit. US liquid units, metric litres, and cubic units are converted with fixed factors stored in the unit table.
Displayed results are rounded for readability. The calculator keeps enough precision for everyday use and switches to scientific notation for very large or very small values. Last reviewed: 2026-05-21.
The US gallon is a liquid volume unit equal to exactly 3.785411784 liters.
HistoryThe US gallon developed from older English wine-gallon measures and differs from the UK imperial gallon.
Current useUS gallons are common for fuel, water, paint, tanks, pools, and household liquid measurements in the United States.
The fluid ounce (UK) (fl oz UK) is a volume unit used to express measurements in this converter.
HistoryThis unit is included because it appears in practical measurement systems, technical references, product specifications, or everyday conversion needs.
Current useUse fluid ounce (UK) when comparing volume values, checking specifications, converting between systems, or preparing quick estimates.
| gallon (US) [gal US] | fluid ounce (UK) [fl oz UK] |
|---|---|
| 1 | 133.22787 |
| 2 | 266.455739 |
| 5 | 666.139348 |
| 10 | 1332.278695 |
| 20 | 2664.557391 |
| 25 | 3330.696739 |
| 50 | 6661.393477 |
| 100 | 13322.786954 |
| 1000 | 133227.869541 |
Use this formula: 1 gallon (US) [gal US] = 133.22787 fluid ounce (UK) [fl oz UK] Enter your value in the calculator and the result updates instantly.
1 gallon (US) [gal US] equals 133.22787 fluid ounce (UK) [fl oz UK].
Yes. Use the swap button in the calculator or open the related reverse conversion link when it is listed on this page.