Litre to Imperial Gallon

Free instant litre to imperial gallon converter. 1 L = 0.219969 gal.

0.219969
Formula
1 L = 0.219969 gal

Common Litre to Imperial Gallon values

Common Litre to Imperial Gallon conversion values.
Litre (L)Imperial Gallon (gal)
10.219969
51.09985
102.19969
255.49923
5010.9985
10021.9969
500109.985
1000219.969

How does Litre to Imperial Gallon conversion work?

Type a value in the Litre (L) field and the equivalent in Imperial Gallon (gal) appears instantly to the right. The math uses the exact formula shown above โ€” no rounding errors, no approximations beyond standard floating-point precision. Use the swap button to flip the units and see the inverse conversion.

Litre. The metric volume unit. About 1.06 US quarts; the volume of a 1 kg block of water.

Imperial Gallon. The UK and Commonwealth gallon. About 4.546 litres โ€” 20% bigger than the US gallon.

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No submit button โ€” the result updates as you type. Math runs entirely in your browser, so itโ€™s as fast as your device.

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Works in any modern browser โ€” Mac, Windows, Linux, iPhone, Android, tablets. No installation, no signup.

๐ŸŽฏ Accurate conversions

Conversion factors come from the official standard (NIST, BIPM, ISO definitions where applicable). Values are precise to standard floating-point limits.

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How it works โ€” the formula

Volume scales as length cubed. 1 L = 1 dmยณ = 0.001 mยณ (exact) 1 US gallon = 3.785411784 L exactly 1 imperial gallon = 4.54609 L exactly (since 1985 redefinition)

Volume is length cubed. The litre is a metric unit equal to one cubic decimetre. The US gallon (3.785411784 L) and imperial gallon (4.54609 L) differ by about 20%; US fluid measurements descend from the 1707 Queen Anne wine gallon, while imperial volumes were redefined in 1985 by the UK Weights and Measures Act in terms of the litre. US dry measurements (bushel, dry quart) form a separate system.

Worked examples

Example 1
US gallon
Inputs:
1 US gal = ? L
Output:
1 ร— 3.785411784 โ‰ˆ 3.7854 L
Example 2
Imperial gallon
Inputs:
1 UK gal = ? L
Output:
1 ร— 4.54609 โ‰ˆ 4.5461 L (~20% larger than US gallon)
Example 3
Cooking
Inputs:
2 cups (US) = ? mL
Output:
2 ร— 236.5882365 โ‰ˆ 473.176 mL

Limitations

  • US fluid ounce (29.5735296875 mL) โ‰  UK fluid ounce (28.4130625 mL) โ‰  avoirdupois weight ounce โ€” all share the name "ounce".
  • A "cup" varies: US legal cup is 240 mL, US customary cup is 236.5882365 mL, metric cup is 250 mL.
  • Dry volumes (bushel, dry pint) follow a different scaling and are not interchangeable with fluid volumes.
  • Gas-volume comparisons require pressure and temperature controls (STP, NTP, IUPAC) โ€” pure unit conversion ignores those.

Conversions are exact rational arithmetic for SI โ†” US fluid โ†” imperial; cooking pages account for US-customary cup-size ambiguities by labelling "US cup" explicitly.

Frequently asked

What is the formula for converting Litre to Imperial Gallon?+
The formula is: 1 L = 0.219969 gal. Type any value into the calculator above and the result appears instantly.
How do I convert Imperial Gallon back to Litre?+
Click the swap button (โ‡„) above to go to the Imperial Gallon โ†’ Litre converter, or use the inverse formula derived from the one shown.
How accurate is the conversion?+
Conversion factors used here are exact rational values from NIST SP 811 and the BIPM SI brochure (e.g. 1 ft = 0.3048 m exactly, 1 lb = 0.45359237 kg exactly). Trailing-digit differences vs hand calculation come only from binary floating-point representation, never from the conversion factor itself.
Where do these conversion factors come from?+
Length and mass factors come from the 1959 international yard-and-pound agreement; SI base units (metre, kilogram, second, kelvin) come from the 2019 BIPM redefinition; energy and pressure factors are NIST SP 811 reference values. Each editorial section above lists the specific source for that category.
Which "gallon" do you use โ€” US or imperial?+
The site's default is the US gallon (3.785411784 L exactly). Imperial / UK gallon (4.54609 L exactly) is roughly 20% larger. When the page title doesn't specify, look at the worked-example output to confirm which definition is in use.

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