Convert US cups to Imperial gallons
1 US cup is 0.05 gal (UK). One US cup is exactly 0.0520421365393 imperial gallons.
One US cup is 0.052042137 imperial gallons. To convert US cups to imperial gallons, multiply by 0.052042137; to go the other way, divide by 0.052042137 or multiply by 19.215199. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST Handbook 130. Eight US fluid ounces, about 236.6 ml.
Factor checked against the defining standard · How we check
- US cups × 0.052042137
1 * 0.05204210.052 gal (UK)
1 US cup in every volume unit
| Unit | Value | Exact factor |
|---|---|---|
| US teaspoons | 48 tsp | × 48 |
| US tablespoons | 16 tbsp | × 16 |
| US fluid ounces | 8 fl oz | × 8 |
| US cups (as entered) | 1 cup | — |
| US pints | 0.5 pt | × 0.5 |
| US quarts | 0.25 qt | × 0.25 |
| US gallons | 0.0625 gal | × 0.0625 |
| milliliters | 236.5882365 ml | × 236.5882365 |
| liters | 0.2365882365 L | × 0.2365882365 |
| imperial gallons | 0.05204213654 gal (UK) | × 0.0520421365393 |
| imperial quarts | 0.2081685462 qt (UK) | × 0.208168546157 |
| imperial pints | 0.4163370923 pt (UK) | × 0.416337092314 |
| imperial fluid ounces | 8.326741846 fl oz (UK) | × 8.32674184629 |
| imperial gills | 1.665348369 gi (UK) | × 1.66534836926 |
| cubic millimetres | 236,588.2365 mm³ | × 236,588.2365 |
| cubic centimetres | 236.5882365 cm³ | × 236.5882365 |
| cubic inches | 14.4375 in³ | × 14.4375 |
| cubic feet | 0.008355034722 ft³ | × 0.00835503472222 |
| cubic yards | 0.0003094457305 yd³ | × 0.000309445730453 |
| cubic metres | 0.0002365882365 m³ | × 0.0002365882365 |
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 US cups to imperial gallons? The converter and the working
- 1.Take the measurement in US cups.
- 2.Multiply by 0.052042137 — that is how many imperial gallons fit in one US cup.
- 3.To go back the other way, divide by 0.052042137, or multiply by 19.215199.
Worked example: 25 US cups to imperial gallons
- Formula
- cup × 0.052042137 = gal (UK)
- Arithmetic
- 25 × 0.052042137 = 1.3 gal (UK)
- Answer
- 25 cup = 1.3 gal (UK)
The factor is rounded for display; the figure above is computed from the full value.
US cups to imperial gallons conversion table
| US cups | Imperial gallons |
|---|---|
| 1 cup | 0.05 gal (UK) |
| 2 cup | 0.1 gal (UK) |
| 3 cup | 0.16 gal (UK) |
| 4 cup | 0.21 gal (UK) |
| 5 cup | 0.26 gal (UK) |
| 6 cup | 0.31 gal (UK) |
| 7 cup | 0.36 gal (UK) |
| 8 cup | 0.42 gal (UK) |
| 9 cup | 0.47 gal (UK) |
| 10 cup | 0.52 gal (UK) |
| 12 cup | 0.62 gal (UK) |
| 15 cup | 0.78 gal (UK) |
| 20 cup | 1.04 gal (UK) |
| 25 cup | 1.3 gal (UK) |
| 50 cup | 2.6 gal (UK) |
| 100 cup | 5.2 gal (UK) |
| 200 cup | 10.41 gal (UK) |
| 300 cup | 15.61 gal (UK) |
| 500 cup | 26.02 gal (UK) |
| 1000 cup | 52.04 gal (UK) |
| 2000 cup | 104.08 gal (UK) |
| 5000 cup | 260.21 gal (UK) |
| 10000 cup | 520.42 gal (UK) |
What is a US cup?
Eight US fluid ounces, about 236.6 ml. The "legal" cup on nutrition labels is a rounded 240 ml.
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.
How many imperial gallons are in a US cup?
One US cup is 0.052042137 imperial gallons. Going the other way, one imperial gallon is 19.215199 US cups. 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 a US cup.
Cite this page
- APA
- Rule Calculator. (2026). Convert US cups to imperial gallons. Rule Calculator. https://rulecalculators.com/convert/cup-to-imperial-gallon
- MLA
- "Convert US cups to imperial gallons." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/cup-to-imperial-gallon.
- Chicago
- Rule Calculator. "Convert US cups to imperial gallons." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/cup-to-imperial-gallon.
The date is when the figures on this page were last checked against their source, not the day you opened it. Add your own access date if your style needs one.
Questions people actually ask
- How many imperial gallons are in a US cup?
- 0.052042137. 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.
- How do I convert imperial gallons back to US cups?
- Divide by 0.052042137, or multiply by 19.215199 — they are the same operation.
Other volume conversions
Imperial gallons to US cups — the same conversion the other way.