A US liquid quart is one quarter of a US gallon.
Quarts to Imperial gallons Converter — qt to imp gal
Convert Quart (qt) to Imperial gallon (imp gal) using the exact conversion factor (1 quart = 0.2081685462 imperial gallon). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Quarts to Imperial gallons 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.
An imperial gallon is exactly 4.54609 liters.
Result = input x 0.000946352946 / 0.00454609.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Quarts to Imperial gallons
Quart and Imperial gallon 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. Quart is typically associated with united States (cooking, dairy, motor oil packaging), while Imperial gallon is typically associated with united Kingdom, Canada (some contexts), and other Commonwealth countries.
Formula
imperial gallons = quarts × 0.208168546157
This factor comes from each unit's defined relationship to the category's base unit: 1 quart equals 0.000946352946 base units, and 1 imperial gallon equals 0.00454609 base units, so dividing one by the other gives the direct quart-to-imperial gallon factor of 0.208168546157.
Simple example
1 qt × 0.2081685462 = 0.2081685462 imp gal
1 quart = 0.2081685462 imperial gallons.
Real-world example
10 qt × 0.2081685462 = 2.081685462 imp gal
10 quarts = 2.081685462 imperial gallons.
Conversion table
| Quart (qt) | Imperial gallon (imp gal) |
|---|---|
| 1 qt | 0.2081685462 imp gal |
| 5 qt | 1.040842731 imp gal |
| 10 qt | 2.081685462 imp gal |
| 25 qt | 5.204213654 imp gal |
| 50 qt | 10.40842731 imp gal |
| 100 qt | 20.81685462 imp gal |
Reverse conversion: Imperial gallon to Quart
0.2081685462 imp gal × 4.803799702 = 1 qt
0.2081685462 imperial gallons = 1 quarts.
quarts = imperial gallons × 4.80379970202
For a page dedicated to this direction, see Imperial gallon to Quart.
Quart vs. Imperial gallon
| Aspect | Quart | Imperial gallon |
|---|---|---|
| Family | US customary unit | UK/imperial customary unit |
| Typical use | US recipe measurement (larger liquid volumes) | UK fuel and beverage measurement (historically; UK now primarily uses liters for retail) |
| Where it's used | United States (cooking, dairy, motor oil packaging) | United Kingdom, Canada (some contexts), and other Commonwealth countries |
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.
Understanding the Imperial gallon
Imperial gallon (imp gal) measures volume. The imperial gallon is defined as exactly 4.54609 liters, about 20% larger than the US gallon. It is classified as a UK/imperial customary unit.
Where it's used: United Kingdom, Canada (some contexts), and other Commonwealth countries
Imperial gallon vs. US gallon. Britain's 1824 Weights and Measures Act defined a new gallon based on 10 pounds of water, replacing the old wine gallon the US had already adopted — leaving the US (3.785 L) and imperial (4.546 L) gallons about 20% apart today.
Uses of the Imperial gallon today
- UK fuel and beverage measurement (historically; UK now primarily uses liters for retail)
- Commonwealth country liquid measurement in some contexts
History of the Imperial gallon
The imperial gallon was created by Britain's Weights and Measures Act of 1824, defined as the volume of 10 pounds of water, replacing several inconsistent older English gallon definitions (wine gallon, ale gallon, corn gallon) with one standard.
Historical origin. Imperial gallon was not the invention of a single named person; it developed through the process described above.
Quart — sources
- NIST Handbook 44, Appendix C — General tables of units including the US quart definition.
Imperial gallon — sources
- UK Weights and Measures Act 1824 — Establishes the imperial gallon definition.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many imperial gallons are in 1 quart?
1 quart equals 0.2081685462 imperial gallons, using the exact defined conversion factor rather than an estimate.
How do I convert quart to imperial gallon?
Multiply the quart value by 0.2081685462. The converter above does this instantly to whatever precision you set.
How do I convert imperial gallon back to quart?
Use the reverse factor: 1 imperial gallon equals 4.803799702 quarts. You can also use the swap control in the converter above to flip the direction instantly.
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.
What is a imperial gallon?
Imperial gallon (imp gal) measures volume. The imperial gallon is defined as exactly 4.54609 liters, about 20% larger than the US gallon. It is classified as a UK/imperial customary unit.
Is the quart to imperial gallon conversion exact?
Yes. The imperial gallon is defined as exactly 4.54609 liters, about 20% larger than the US gallon. 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 gallon vs. us gallon?
Britain's 1824 Weights and Measures Act defined a new gallon based on 10 pounds of water, replacing the old wine gallon the US had already adopted — leaving the US (3.785 L) and imperial (4.546 L) gallons about 20% apart today.
Where is the quart still used today?
United States (cooking, dairy, motor oil packaging)