What is teaspoon (metric)?

A metric teaspoon is a volume unit equal to exactly 5 millilitres. It is a standard unit in cooking recipes and pharmaceutical dosing instructions across metric countries.

Real-world uses

The metric teaspoon (5 mL) is used in cooking recipes, pharmaceutical dosing instructions, and nutrition labelling. It is the standard dosing spoon for children's liquid medicines. Most international recipes specify teaspoon measurements assuming the 5 mL metric standard.

History

The teaspoon originated as a unit of apothecary measure in the 18th century, roughly the volume of a small spoon used to stir tea. The metric teaspoon was standardized at exactly 5 mL to align with the metric system and simplify pharmaceutical dosing.

Common mistakes

Confusing the metric teaspoon (5 mL) with the US customary teaspoon (4.929 mL) or the older Imperial teaspoon (3.55 mL). Also, using a household spoon instead of a measuring spoon—actual spoons vary widely in size.

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.

When is this conversion used?

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

Worked examples

1 teaspoon (metric) = 0.00109985 Imperial gallon

1 Imperial gallon = 4.54609 litre

How to convert teaspoon (metric) to Imperial gallon

To convert teaspoon (metric) to Imperial gallon, multiply the value by 0.00109985.

To convert Imperial gallon back to teaspoon (metric), multiply by 909.218.

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: teaspoon (metric) to Imperial gallon

teaspoon (metric)Imperial gallon
0.10.00010998
0.50.00054992
10.00109985
20.00219969
50.00549923
100.01099846
250.02749616
500.05499231
1000.10998462
2500.27496156
5000.54992312
1,0001.09984624

Common values

teaspoon (metric)Imperial gallon
A teaspoon1 teaspoon (metric)0.00109985 Imperial gallon
A cup of coffee50 teaspoon (metric)0.05499231 Imperial gallon
A water bottle100 teaspoon (metric)0.10998462 Imperial gallon
A bathtub60,000 teaspoon (metric)65.99077449 Imperial gallon
A swimming pool (Olympic)500,000,000 teaspoon (metric)549,923.12074772 Imperial gallon