Convert Imperial gallons to Liters
1 imperial gallon is 4.55 L. One imperial gallon is exactly 4.54609 liters.
One imperial gallon is 4.54609 liters. To convert imperial gallons to liters, multiply by 4.54609; to go the other way, divide by 4.54609 or multiply by 0.21996925. The factor is exact rather than rounded: it follows from NIST Handbook 130.
Factor checked against the defining standard · How we check
- Imperial gallons × 4.54609
1 * 4.546094.546 L
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.
The same converter answers this pair however it is written: imperial gallons to litres is the British spelling of the same units — the metre and the litre are spelled that way outside the United States and the quantity does not change.
How do you convert imperial gallons to liters? The converter and the working
- 1.Take the measurement in imperial gallons.
- 2.Multiply by 4.54609 — that is how many liters fit in one imperial gallon.
- 3.To go back the other way, divide by 4.54609, or multiply by 0.21996925.
Worked example: 25 imperial gallons to liters
- Formula
- gal (UK) × 4.54609 = L
- Arithmetic
- 25 × 4.54609 = 113.65 L
- Answer
- 25 gal (UK) = 113.65 L
The factor is exact, so this figure is exact too — only the display is rounded.
Imperial gallons to liters conversion table
| Imperial gallons | Liters |
|---|---|
| 1 gal (UK) | 4.55 L |
| 2 gal (UK) | 9.09 L |
| 3 gal (UK) | 13.64 L |
| 4 gal (UK) | 18.18 L |
| 5 gal (UK) | 22.73 L |
| 6 gal (UK) | 27.28 L |
| 7 gal (UK) | 31.82 L |
| 8 gal (UK) | 36.37 L |
| 9 gal (UK) | 40.91 L |
| 10 gal (UK) | 45.46 L |
| 12 gal (UK) | 54.55 L |
| 15 gal (UK) | 68.19 L |
| 20 gal (UK) | 90.92 L |
| 25 gal (UK) | 113.65 L |
| 50 gal (UK) | 227.3 L |
| 100 gal (UK) | 454.61 L |
| 200 gal (UK) | 909.22 L |
| 300 gal (UK) | 1,363.83 L |
| 500 gal (UK) | 2,273.05 L |
| 1000 gal (UK) | 4,546.09 L |
| 2000 gal (UK) | 9,092.18 L |
| 5000 gal (UK) | 22,730.45 L |
| 10000 gal (UK) | 45,460.9 L |
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 a liter?
One cubic decimeter. A liter of water weighs almost exactly one kilogram, which is how the unit was designed.
How many liters are in an imperial gallon?
One imperial gallon is 4.54609 liters, exactly. Going the other way, one liter is 0.21996925 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 liters. Rule Calculator. https://rulecalculators.com/convert/imperial-gallon-to-liter
- MLA
- "Convert Imperial gallons to liters." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/imperial-gallon-to-liter.
- Chicago
- Rule Calculator. "Convert Imperial gallons to liters." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/imperial-gallon-to-liter.
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Questions people actually ask
- How many liters are in an imperial gallon?
- 4.54609. One cubic decimeter. A liter of water weighs almost exactly one kilogram, which is how the unit was designed.
- How do I convert liters back to imperial gallons?
- Divide by 4.54609, or multiply by 0.21996925 — they are the same operation.
Other volume conversions
Liters to imperial gallons — the same conversion the other way.