What is Imperial gallon?

An Imperial gallon is a volume unit used in the United Kingdom equal to approximately 4.546 litres. It is larger than the US gallon and is commonly referenced for fuel efficiency (miles per gallon) in the UK.

Real-world uses

Imperial gallons are used in the United Kingdom, Canada (for some purposes), and several Caribbean countries. British fuel economy was historically quoted in miles per Imperial gallon. Older Commonwealth-era recipes and industrial specifications may reference Imperial gallons.

History

The Imperial gallon was established by the British Weights and Measures Act of 1824 as the volume occupied by 10 pounds of water at 62°F (≈ 17°C). It replaced several older gallon definitions including the wine gallon (retained by the US) and the ale gallon.

Common mistakes

Assuming the Imperial gallon equals the US gallon. The Imperial gallon is about 4.546 litres versus 3.785 litres for the US gallon. Converting mpg figures between the two systems without adjusting for gallon size gives misleading results.

What is tablespoon (metric)?

A metric tablespoon is a volume unit equal to exactly 15 millilitres. It is widely used in cooking recipes in metric countries as a convenient measure for sauces, oils, and seasonings.

Real-world uses

The metric tablespoon (15 mL) is used in cooking recipes worldwide, particularly for oil, vinegar, sauces, and spices. It is also a common dosing measure for adult liquid medicines. Nutritional databases often list serving sizes in tablespoons.

History

The tablespoon evolved from the table or serving spoon and was adopted as a cooking measure. The metric tablespoon was standardized at 15 mL (3 metric teaspoons). In Australia, the tablespoon was standardized at 20 mL, creating a regional exception.

Common mistakes

Assuming a tablespoon is always 15 mL—the Australian tablespoon is 20 mL, and the US customary tablespoon is 14.79 mL. Failing to check which standard a recipe uses can alter the outcome of precise baking recipes.

When is this conversion used?

Converting Imperial gallon to tablespoon (metric) is useful in the volume domain when comparing values across different measurement standards or applying formulas that require a specific unit.

Worked examples

1 Imperial gallon = 303.07266667 tablespoon (metric)

1 tablespoon (metric) = 0.015 litre

How to convert Imperial gallon to tablespoon (metric)

To convert Imperial gallon to tablespoon (metric), multiply the value by 303.07266667.

To convert tablespoon (metric) back to Imperial gallon, multiply by 0.00329954.

Measurement standards

The cubic metre is the SI derived unit of volume. The litre, equal to exactly one cubic decimetre (0.001 m³), is accepted by the BIPM for use alongside SI units. Both the lowercase "l" and uppercase "L" are approved symbols for the litre.

Did you know?

An Olympic swimming pool holds 2,500 cubic metres of water — about 2.5 million litres. The Amazon River discharges roughly 209,000 cubic metres per second, enough to fill 84 Olympic pools every single second.

Quick reference: Imperial gallon to tablespoon (metric)

Imperial gallontablespoon (metric)
0.130.30726667
0.5151.53633333
1303.07266667
2606.14533333
51,515.36333333
103,030.72666667
257,576.81666667
5015,153.63333333
10030,307.26666667
25075,768.16666667
500151,536.33333333
1,000303,072.66666667

Common values

Imperial gallontablespoon (metric)
A teaspoon0.00109985 Imperial gallon0.33333333 tablespoon (metric)
A cup of coffee0.05499231 Imperial gallon16.66666667 tablespoon (metric)
A water bottle0.10998462 Imperial gallon33.33333333 tablespoon (metric)
A bathtub65.99077449 Imperial gallon20,000 tablespoon (metric)
A swimming pool (Olympic)549,923.12074772 Imperial gallon166,666,666.66666669 tablespoon (metric)

Available Volume units

More Imperial gallon conversions