An imperial fluid ounce is 1/160 of an imperial gallon.
Imperial fluid ounces to Quarts Converter — imp fl oz to qt
Convert Imperial fluid ounce (imp fl oz) to Quart (qt) using the exact conversion factor (1 imperial fluid ounce = 0.0300237481 quart). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Imperial fluid ounces to Quarts converter
Converter
Volume Converter
Convert metric, US customary, imperial, cooking, dry, and industrial volume units.
Context values
Some unit families need one extra value for a physically accurate result.
A US liquid quart is one quarter of a US gallon.
Result = input x 2.84130625e-5 / 0.000946352946.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Imperial fluid ounces to Quarts
Imperial fluid ounce and Quart appear side by side at fuel pumps and on beverage labels, since the US measures liquids in gallons while most of the world uses liters. Imperial fluid ounce is typically associated with united Kingdom (historically; less common in current UK retail than metric units), while Quart is typically associated with united States (cooking, dairy, motor oil packaging).
Formula
quarts = imperial fluid ounces × 0.0300237481376
This factor comes from each unit's defined relationship to the category's base unit: 1 imperial fluid ounce equals 0.0000284130625 base units, and 1 quart equals 0.000946352946 base units, so dividing one by the other gives the direct imperial fluid ounce-to-quart factor of 0.0300237481376.
Simple example
1 imp fl oz × 0.03002374814 = 0.0300237481 qt
1 imperial fluid ounce = 0.0300237481 quarts.
Real-world example
10 imp fl oz × 0.03002374814 = 0.3002374814 qt
10 imperial fluid ounces = 0.3002374814 quarts.
Conversion table
| Imperial fluid ounce (imp fl oz) | Quart (qt) |
|---|---|
| 1 imp fl oz | 0.0300237481 qt |
| 5 imp fl oz | 0.1501187407 qt |
| 10 imp fl oz | 0.3002374814 qt |
| 25 imp fl oz | 0.7505937034 qt |
| 50 imp fl oz | 1.501187407 qt |
| 100 imp fl oz | 3.002374814 qt |
Reverse conversion: Quart to Imperial fluid ounce
0.0300237481 qt × 33.30696739 = 0.9999999987 imp fl oz
0.0300237481 quarts = 0.9999999987 imperial fluid ounces.
imperial fluid ounces = quarts × 33.3069673852
For a page dedicated to this direction, see Quart to Imperial fluid ounce.
Imperial fluid ounce vs. Quart
| Aspect | Imperial fluid ounce | Quart |
|---|---|---|
| Family | UK/imperial customary unit | US customary unit |
| Typical use | UK/Commonwealth beverage measurement in historical or specialized contexts | US recipe measurement (larger liquid volumes) |
| Where it's used | United Kingdom (historically; less common in current UK retail than metric units) | United States (cooking, dairy, motor oil packaging) |
Understanding the Imperial fluid ounce
Imperial fluid ounce (imp fl oz) measures volume. The imperial fluid ounce is 1/160 of an imperial gallon: exactly 28.4130625 milliliters — slightly smaller than the US fluid ounce despite the larger imperial gallon, because it divides that gallon into more parts. It is classified as a UK/imperial customary unit.
Where it's used: United Kingdom (historically; less common in current UK retail than metric units)
Imperial fluid ounce vs. US fluid ounce. Confusingly, the imperial fluid ounce (28.41 mL) is slightly smaller than the US fluid ounce (29.57 mL), even though the imperial gallon is larger overall — because the imperial gallon is divided into 160 fluid ounces rather than the US gallon's 128.
Uses of the Imperial fluid ounce today
- UK/Commonwealth beverage measurement in historical or specialized contexts
History of the Imperial fluid ounce
The imperial fluid ounce follows from Britain's 1824 imperial gallon, divided into 160 parts rather than the 128 used in the US system, producing its counterintuitively smaller size relative to the US fluid ounce.
Historical origin. Imperial fluid ounce was not the invention of a single named person; it developed through the process described above.
Understanding the Quart
Quart (qt) measures volume. The US liquid quart is exactly one-quarter of a US gallon: 0.946352946 liters. It is classified as a US customary unit.
Where it's used: United States (cooking, dairy, motor oil packaging)
Uses of the Quart today
- US recipe measurement (larger liquid volumes)
- US motor oil and automotive fluid packaging
- US dairy and beverage packaging (quart containers)
History of the Quart
The quart ('quarter' of a gallon) follows the same English wine-gallon lineage as the US gallon, retained by the US after England moved to a different imperial standard in 1824.
Historical origin. Quart was not the invention of a single named person; it developed through the process described above.
Imperial fluid ounce — sources
- UK Weights and Measures Act 1824 — Basis for the imperial fluid ounce via the imperial gallon.
Quart — sources
- NIST Handbook 44, Appendix C — General tables of units including the US quart definition.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many quarts are in 1 imperial fluid ounce?
1 imperial fluid ounce equals 0.0300237481 quarts, using the exact defined conversion factor rather than an estimate.
How do I convert imperial fluid ounce to quart?
Multiply the imperial fluid ounce value by 0.03002374814. The converter above does this instantly to whatever precision you set.
How do I convert quart back to imperial fluid ounce?
Use the reverse factor: 1 quart equals 33.30696739 imperial fluid ounces. You can also use the swap control in the converter above to flip the direction instantly.
What is a imperial fluid ounce?
Imperial fluid ounce (imp fl oz) measures volume. The imperial fluid ounce is 1/160 of an imperial gallon: exactly 28.4130625 milliliters — slightly smaller than the US fluid ounce despite the larger imperial gallon, because it divides that gallon into more parts. It is classified as a UK/imperial customary unit.
What is a quart?
Quart (qt) measures volume. The US liquid quart is exactly one-quarter of a US gallon: 0.946352946 liters. It is classified as a US customary unit.
Is the imperial fluid ounce to quart conversion exact?
Yes. The US liquid quart is exactly one-quarter of a US gallon: 0.946352946 liters. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between imperial fluid ounce vs. us fluid ounce?
Confusingly, the imperial fluid ounce (28.41 mL) is slightly smaller than the US fluid ounce (29.57 mL), even though the imperial gallon is larger overall — because the imperial gallon is divided into 160 fluid ounces rather than the US gallon's 128.
Where is the imperial fluid ounce still used today?
United Kingdom (historically; less common in current UK retail than metric units)