Volume / US cup → imp gal
Convert US customary cups to Imperial gallons
Convert liters, milliliters, cubic meters, and clearly labeled US and imperial measures for liquids and capacity. Convert US customary cups (US cup) to Imperial gallons (imp gal). Find the formula, worked examples, unit definitions, and practical guidance below.
Reverse: Imperial gallons to US customary cups →
How to convert US customary cups to imperial gallons
US customary, imperial, and metric kitchen measures can have different sizes despite similar names. Use the system printed on your recipe or container.
Use x for the value in US cup, b for the intermediate value in L, and y for the result in imp gal.
imp gal = US cup × 0.2365882365 ÷ 4.54609
Worked examples
10 US cup ≈ 0.520421365393 imp gal
Step 1: (10 × 0.2365882365) ≈ 2.365882365 L.
Step 2: 2.365882365 ÷ 4.54609 ≈ 0.520421365393 imp gal.20 US cup ≈ 1.04084273079 imp gal
Step 1: (20 × 0.2365882365) ≈ 4.73176473 L.
Step 2: 4.73176473 ÷ 4.54609 ≈ 1.04084273079 imp gal.
Results are rounded to 12 significant digits. Converting units does not increase the precision of the original measurement. Very large or small values outside JavaScript’s finite numeric range are rejected.
About US customary cups
A US customary cup is half a US liquid pint, or exactly 236.5882365 milliliters. This is not a 240 mL nutrition-label cup or a 250 mL metric cup.
About Imperial gallons
An imperial gallon is exactly 4.54609 liters. Its capacity is greater than a US liquid gallon, so labels that only say “gallons” need a system check.
Definitions and sources
Check which gallon, cup, or ounce you mean
A US liquid gallon contains 3.785411784 liters; an imperial gallon contains 4.54609 liters. This calculator labels both explicitly and does not substitute one for the other.
Our US customary cup is 236.5882365 mL. A recipe may instead use a 250 mL metric cup or a 240 mL cup. Fluid ounces measure volume, while ounces in the Weight category measure mass.
For a tank or room, calculate the volume using dimensions in the same length unit before converting its cubic units. Changing only one side’s unit will give an incorrect volume.
Check the cup or fluid-ounce convention before using a converted volume in recipe calculations.
US customary cups to imperial gallons reference table
| US customary cups (US cup) | Imperial gallons (imp gal) |
|---|---|
| 1 | 0.0520421365393 |
| 5 | 0.260210682697 |
| 10 | 0.520421365393 |
| 25 | 1.30105341348 |
| 50 | 2.60210682697 |
| 100 | 5.20421365393 |
| 1000 | 52.0421365393 |
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