Convert Imperial gallons to Imperial fluid ounces
1 imperial gallon is 160 fl oz (UK). One imperial gallon is exactly 160 imperial fluid ounces.
One imperial gallon is 160 imperial fluid ounces. To convert imperial gallons to imperial fluid ounces, multiply by 160; to go the other way, divide by 160 or multiply by 0.00625. The factor is exact rather than rounded: it follows from NIST Handbook 130.
Factor checked against the defining standard · How we check
- Imperial gallons × 160
1 * 160160 fl oz (UK)
1 imperial gallon in every volume unit
| Unit | Value | Exact factor |
|---|---|---|
| US teaspoons | 922.3295428 tsp | × 922.329542788 |
| US tablespoons | 307.4431809 tbsp | × 307.443180929 |
| US fluid ounces | 153.7215905 fl oz | × 153.721590465 |
| US cups | 19.21519881 cup | × 19.2151988081 |
| US pints | 9.607599404 pt | × 9.60759940404 |
| US quarts | 4.803799702 qt | × 4.80379970202 |
| US gallons | 1.200949926 gal | × 1.2009499255 |
| milliliters | 4,546.09 ml | × 4,546.09 |
| liters | 4.54609 L | × 4.54609 |
| imperial gallons (as entered) | 1 gal (UK) | — |
| imperial quarts | 4 qt (UK) | × 4 |
| imperial pints | 8 pt (UK) | × 8 |
| imperial fluid ounces | 160 fl oz (UK) | × 160 |
| imperial gills | 32 gi (UK) | × 32 |
| cubic millimetres | 4,546,090 mm³ | × 4,546,090 |
| cubic centimetres | 4,546.09 cm³ | × 4,546.09 |
| cubic inches | 277.4194328 in³ | × 277.419432792 |
| cubic feet | 0.1605436532 ft³ | × 0.160543653236 |
| cubic yards | 0.005946061231 yd³ | × 0.00594606123096 |
| cubic metres | 0.00454609 m³ | × 0.00454609 |
Factors are entered by hand from NIST Handbook 130 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert imperial gallons to imperial fluid ounces? The converter and the working
- 1.Take the measurement in imperial gallons.
- 2.Multiply by 160 — that is how many imperial fluid ounces fit in one imperial gallon.
- 3.To go back the other way, divide by 160, or multiply by 0.00625.
Worked example: 25 imperial gallons to imperial fluid ounces
- Formula
- gal (UK) × 160 = fl oz (UK)
- Arithmetic
- 25 × 160 = 4,000 fl oz (UK)
- Answer
- 25 gal (UK) = 4,000 fl oz (UK)
The factor is exact, so this figure is exact too — only the display is rounded.
Imperial gallons to imperial fluid ounces conversion table
| Imperial gallons | Imperial fluid ounces |
|---|---|
| 1 gal (UK) | 160 fl oz (UK) |
| 2 gal (UK) | 320 fl oz (UK) |
| 3 gal (UK) | 480 fl oz (UK) |
| 4 gal (UK) | 640 fl oz (UK) |
| 5 gal (UK) | 800 fl oz (UK) |
| 6 gal (UK) | 960 fl oz (UK) |
| 7 gal (UK) | 1,120 fl oz (UK) |
| 8 gal (UK) | 1,280 fl oz (UK) |
| 9 gal (UK) | 1,440 fl oz (UK) |
| 10 gal (UK) | 1,600 fl oz (UK) |
| 12 gal (UK) | 1,920 fl oz (UK) |
| 15 gal (UK) | 2,400 fl oz (UK) |
| 20 gal (UK) | 3,200 fl oz (UK) |
| 25 gal (UK) | 4,000 fl oz (UK) |
| 50 gal (UK) | 8,000 fl oz (UK) |
| 100 gal (UK) | 16,000 fl oz (UK) |
| 200 gal (UK) | 32,000 fl oz (UK) |
| 300 gal (UK) | 48,000 fl oz (UK) |
| 500 gal (UK) | 80,000 fl oz (UK) |
| 1000 gal (UK) | 160,000 fl oz (UK) |
| 2000 gal (UK) | 320,000 fl oz (UK) |
| 5000 gal (UK) | 800,000 fl oz (UK) |
| 10000 gal (UK) | 1,600,000 fl oz (UK) |
What is an imperial gallon?
Exactly 4.54609 liters since 1985, and the reason UK and US fuel economy figures cannot be compared: it is 20% larger than the US gallon, so 40 mpg in Britain is about 33 mpg in America on the same car.
What is an imperial fluid ounce?
One 160th of an imperial gallon, 28.4130625 ml exactly. The US fluid ounce is one 128th of a smaller gallon at 29.57 ml, so the two ounces differ by about 4% in the opposite direction to the gallons.
How many imperial fluid ounces are in an imperial gallon?
One imperial gallon is 160 imperial fluid ounces, exactly. Going the other way, one imperial fluid ounce is 0.00625 imperial gallons. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every volume unit here
The whole group — 20 units with their symbols and the size of each one in liters — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to an imperial gallon.
Cite this page
- APA
- Rule Calculator. (2026). Convert Imperial gallons to imperial fluid ounces. Rule Calculator. https://rulecalculators.com/convert/imperial-gallon-to-imperial-fluid-ounce
- MLA
- "Convert Imperial gallons to imperial fluid ounces." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/imperial-gallon-to-imperial-fluid-ounce.
- Chicago
- Rule Calculator. "Convert Imperial gallons to imperial fluid ounces." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/imperial-gallon-to-imperial-fluid-ounce.
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Questions people actually ask
- How many imperial fluid ounces are in an imperial gallon?
- 160. One 160th of an imperial gallon, 28.4130625 ml exactly. The US fluid ounce is one 128th of a smaller gallon at 29.57 ml, so the two ounces differ by about 4% in the opposite direction to the gallons.
- How do I convert imperial fluid ounces back to imperial gallons?
- Divide by 160, or multiply by 0.00625 — they are the same operation.
Other volume conversions
Imperial fluid ounces to imperial gallons — the same conversion the other way.