Imperial Gallons to Metric Teaspoons (gal (UK) to tsp)

1 imperial gallon equals 909.218 metric teaspoons exactly.

1 imperial gallon = 909.218 metric teaspoons

How to convert imperial gallons to metric teaspoons

To convert imperial gallons to metric teaspoons, multiply the number of imperial gallons by 909.218. This factor is exact. To go the other way, multiply metric teaspoons by 0.001099846241 (rounded).

metric teaspoons = imperial gallons × 909.218

Example: 10 imperial gallons = 9,092.18 metric teaspoons.

Pints, quarts, gallons and fluid ounces differ between the US and the UK. Units are labeled 'US' or 'imperial' to avoid confusion.

About these units

Imperial Gallon (gal (UK))

Imperial (British)Current unit

Exactly 4.54609 liters, the volume of 10 pounds of water. Used for fuel economy in the UK (miles per gallon) and historically across the Commonwealth.

Britain unified its confusing gallons by act of Parliament in 1824. Before then, the country used separate ones for wine at 231 cubic inches, ale at 282 and corn at about 268.8. The 1824 reform replaced them with the imperial gallon, defined as the volume of ten pounds of distilled water, calculated at 277.274 cubic inches. A new definition in 1889 slightly changed that, and after the liter was restored to exactly a cubic decimeter in 1964, Canada and then the UK in 1976 adopted the exact value of 4.54609 liters.

Because the United States kept the 231-cubic-inch wine gallon, an imperial gallon is about 20 percent larger than a US gallon. That explains why a car rated at 40 miles per gallon in Britain is less impressive in American terms, since it comes to roughly 33 US miles per gallon. Ireland dropped the gallon as a primary trade unit at the end of 1993 and the UK at the end of September 1995, but it lives on in British fuel-economy figures and older recipes.

1 imperial gallon = 4.54609 liters (exactly).

Sources: Wikipedia: Gallon; UK Weights and Measures Act 1985, Schedule 1

Metric Teaspoon (tsp)

Cooking & barCurrent unit

Exactly 5 mL, used in most countries.

Five milliliters is the metric teaspoon, a figure so tidy that it has become the working definition for medicine and food labels. The traditional British teaspoon was an imperial fluid drachm, one eighth of an imperial fluid ounce, about 3.55 milliliters, and the American one was 4.93 mL. US nutrition labeling law now defines a teaspoon as exactly 5 milliliters.

The 5 mL teaspoon matters most when dosing medicine. Kitchen spoons vary widely, with one Greek survey of 71 household teaspoons finding volumes from 2.5 to 7.3 mL, so measuring spoons, syringes and calibrated cups are the safer tools. It also anchors the metric cooking system: three teaspoons make a 15 mL tablespoon, and fifty fit in a 250 mL metric cup. Australia keeps a 5 mL teaspoon but counts four of them in its larger 20 mL tablespoon.

1 metric teaspoon = 0.005 liters (exactly).

Sources: Wikipedia: Teaspoon; 21 CFR 101.9: nutrition labeling household measures; Wikipedia: Metric cup

Related conversions

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