Teaspoons to Millilitres Converter
Metric 5 mL, US 4.929 mL. Pick below.
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Five millilitres
A metric teaspoon is exactly 5 mL. A US teaspoon is 4.929 mL. The 1.4 % difference is meaningless in a kitchen, so five is the number to remember.
1 metric tsp = 5 mL exactly
This matters most for medicine. A 5 mL dose is one teaspoon — but household spoons vary enormously, and studies have found people delivering anywhere from 3 to 9 mL with one. Use the supplied measure for anything medical.
Unlike the tablespoon, the teaspoon is 5 mL in Australia too.
The teaspoon
A US teaspoon is 4.929 mL; a metric teaspoon is exactly 5 mL. The 1.4 % difference is below what a kitchen spoon can measure, so the two are interchangeable in practice.
Three teaspoons make a tablespoon in both the US and metric systems.
The millilitre
A thousandth of a litre, and exactly one cubic centimetre. That equivalence is exact by definition, not an approximation — the litre was defined as a cubic decimetre, so a thousandth of it is a cubic centimetre.
It is the everyday unit for liquids across most of the world: medicine doses, recipes, drinks and fuel measurements.
The working, step by step
Every line updates with whatever you type above. The point is the method, which is the same for any pair of units in this family.
The same quantity, two different numbers
One physical amount, read off two scales. The tick marks do not line up, and the gap between them is the conversion factor made visible.
How much is that?
A number is easier to judge next to something familiar.
Your turn
Reading a method and being able to use it are different things. Answer within half a per cent and it counts as correct.
Score: 0 of 0
How to use this converter
- Type into either box. The other side updates as you go; there is no button to press.
- Swap the direction with the button between the boxes, carrying your value across.
- Set the decimals if the default is more or less precision than you need.
- Copy the answer with its unit, ready to paste.
- Use the shortcut buttons for the values that come up most often.
- Share the result. The address bar tracks what you type, so the link you copy opens on the same number.
Common uses and tips
Where volume conversions come up
- Cooking from a foreign recipe. The commonest reason, and the one where getting it wrong shows.
- Medicine doses, given in millilitres worldwide and sometimes in teaspoons at home — a genuinely risky place to guess.
- Fuel, where miles per gallon means two different things depending on which side of the Atlantic wrote the figure.
- Engine sizes, quoted in cubic inches, cubic centimetres or litres depending on the market and the decade.
- Building materials such as concrete and topsoil, sold by the cubic yard or cubic metre.
The big one: US and Imperial are different sizes
These are not two names for the same unit. They are different volumes.
- Gallon — US 3.785 L, Imperial 4.546 L. The Imperial one is about 20 % larger.
- Pint — US 473 mL (16 fl oz), Imperial 568 mL (20 fl oz).
- Quart — US 946 mL, Imperial 1,137 mL.
- Fluid ounce — US 29.57 mL, Imperial 28.41 mL. Here the US one is the larger, which catches everyone.
The reason for that last oddity is historical. The US kept the old English wine gallon of 231 cubic inches and divided it into 128 fluid ounces. Britain redefined its gallon in 1824 as ten pounds of water and divided it into 160. More ounces in a bigger gallon means each ounce comes out smaller.
The practical upshot: a British recipe's pint is a fifth more liquid than an American one, and 30 mpg in Britain is about 25 mpg in the United States.
Fluid ounces are not ounces
A fluid ounce measures volume; an ounce measures mass. They are related only for water, where a US fluid ounce weighs about 1.04 oz. For flour, honey or oil the two figures are nowhere near each other, which is why baking by weight is more reliable than baking by cups.
Tips worth knowing
- 1 mL is exactly 1 cm³. Not approximately — exactly, by definition.
- Australian tablespoons are 20 mL, against 15 mL everywhere else. Three tablespoons of an Australian recipe is 60 mL.
- Cubic conversions cube the length factor. A foot is 0.3048 m, so a cubic foot is 0.3048³ = 0.0283 m³.
- Weigh, do not measure, for baking. A cup of flour varies by 20 % depending on how it was packed.
Values people look up most
Each one opens the converter with the number already in it.
- 0.25 tsp to mL
- 0.5 tsp to mL
- 0.75 tsp to mL
- 1 tsp to mL
- 1.5 tsp to mL
- 2 tsp to mL
- 3 tsp to mL
- 4 tsp to mL
- 5 tsp to mL
- 6 tsp to mL
- 8 tsp to mL
- 12 tsp to mL
Quick reference
Using US teaspoons of 4.929 mL.
| Teaspoons | Millilitres |
|---|---|
| 0.5 tsp | 2.464461 mL |
| 1 tsp | 4.928922 mL |
| 2 tsp | 9.857843 mL |
| 3 tsp | 14.786765 mL |
| 4 tsp | 19.715686 mL |
| 6 tsp | 29.57353 mL |
| 12 tsp | 59.147059 mL |
Questions people ask
How many mL in a teaspoon?
5 mL metric, 4.929 mL US.
Is an Australian teaspoon different?
No. Only the Australian tablespoon differs, at 20 mL.
Can I use a kitchen spoon for medicine?
Not reliably. Studies show household spoons deliver anywhere from about 3 to 9 mL. Use the measure that comes with the medicine.