This converter turns imperial fluid ounces into US gallons instantly, using the exact factor 1 imperial fluid ounce = 0.007505937034 US gallons. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
The UK fluid ounce, about 4% smaller than its US counterpart. Exactly 231 cubic inches — the US liquid gallon used for fuel and milk.
Because the relationship is a simple proportion, one multiplication does the whole job. The table further down gives pre-computed values for the amounts people look up most often, and the result panel also reports the reverse conversion so you can check the figure both ways.
The formula
imperial fluid ounces- The amount you are converting, measured in imperial fluid ounces
0.007505937034- The exact number of US gallons in one imperial fluid ounce
US gallons- The converted result
How it works, step by step
- Enter the number of imperial fluid ounces you want to convert.
- The value is multiplied by 0.007505937034, the exact conversion factor.
- The result is displayed in US gallons, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 imperial fluid ounces
Multiply 5 by 0.007505937. That gives 0.03753 US gallons. A quick sanity check: one imperial fluid ounce is smaller than one US gallon, so the number should get smaller — and it does.
Converting 72 imperial fluid ounces
72 × 0.007505937 = 0.540427 US gallons. Working backwards, 0.540427 ÷ 0.007505937 returns 72 imperial fluid ounces, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many US gallons are in one imperial fluid ounce?
Exactly 0.007505937034. Every conversion on this page is that single number multiplied by your input, so the result carries no rounding error beyond what is shown.
What is the formula to convert imperial fluid ounces to US gallons?
Us Gallons = imperial fluid ounces × 0.007505937034. To reverse it, divide instead: imperial fluid ounces = US gallons ÷ 0.007505937034, which is the same as multiplying by 133.2278695.
Is the imperial fluid ounce bigger than the US gallon?
No. One imperial fluid ounce is only 0.00750594 of a US gallon, so the US gallon is the larger unit.
Why does my answer differ slightly from other imperial-fluid-ounces to us-gallons converters?
Most differences come from rounding the factor too early. This tool keeps full double precision through the calculation and only rounds at the final display step, and it also shows the unrounded value so you can see exactly where any difference appears.
What is a imperial fluid ounce?
The UK fluid ounce, about 4% smaller than its US counterpart.
What is a US gallon?
Exactly 231 cubic inches — the US liquid gallon used for fuel and milk.
Imperial Fluid Ounces to US gallons reference table
| Imperial Fluid Ounces | Us Gallons |
|---|---|
| 0.5 fl oz | 0.003753 gal |
| 1 fl oz | 0.007506 gal |
| 2 fl oz | 0.015012 gal |
| 3 fl oz | 0.022518 gal |
| 5 fl oz | 0.03753 gal |
| 10 fl oz | 0.075059 gal |
| 15 fl oz | 0.112589 gal |
| 20 fl oz | 0.150119 gal |
| 25 fl oz | 0.187648 gal |
| 50 fl oz | 0.375297 gal |
| 75 fl oz | 0.562945 gal |
| 100 fl oz | 0.750594 gal |
| 250 fl oz | 1.8765 gal |
| 500 fl oz | 3.753 gal |
| 1000 fl oz | 7.5059 gal |
Exact factor: 1 imperial fluid ounce = 0.007505937034 US gallons. Values rounded for display.