The US teaspoon, unit of volume
The US teaspoon holds exactly 4.92892159375 milliliters, that is a sixth of a US fluid ounce and a third of a US tablespoon. It is the smallest measure an American recipe uses, and the one most often taken from a drawer instead of a measuring set.
There are two teaspoons in an American kitchen and only one of them is a spoon. The cooking teaspoon holds 4.93 milliliters; the teaspoon of medicine holds 5 exactly; and a spoon taken from the drawer holds anywhere between two and a half and seven, depending on the pattern. The American Academy of Pediatrics recommended in 2015 that liquid medicines for children be prescribed and measured in milliliters alone, precisely to take the word teaspoon out of the chain between the prescription and the child.
The US teaspoon in other units
| 1 tsp | 0.00000492892 m³ |
| 1 tsp | 0.00492892 l |
| 1 tsp | 0.492892 cl |
| 1 tsp | 4.92892 ml |
| 1 tsp | 0.00130208 gal |
| 1 tsp | 0.00108421 gal UK |
| 1 tsp | 0.0104167 pt |
| 1 tsp | 0.166667 fl oz |
| 1 tsp | 0.173474 fl oz UK |
| 1 tsp | 0.00520833 qt |
| 1 tsp | 0.00433684 qt UK |
| 1 tsp | 0.00867369 pt UK |
| 1 tsp | 0.0208333 cup |
| 1 tsp | 0.0197157 cup metric |
| 1 tsp | 0.0246446 cup JP |
| 1 tsp | 0.333333 tbsp |
| 1 tsp | 0.328595 tbsp metric |
| 1 tsp | 0.246446 tbsp AU |
| 1 tsp | 0.985784 tsp metric |
| 1 tsp | 0.0492892 dl |
| 1 tsp | 0.000031002 bbl |
| 1 tsp | 0.00273236 sho |
| 1 tsp | 0.0273236 go |
Frequently asked questions
How many milliliters are in a US teaspoon?
4.92892159375 exactly, which everyone rounds to 4.93 or simply to 5. The metric teaspoon is 5 milliliters exactly, so the two differ by one and a half per cent, which no recipe will ever notice.
Can I use a kitchen spoon to give medicine?
No, and that is the one place where the difference matters. Teaspoons from a drawer are not measures at all and vary by a factor of nearly three; a dosing syringe or a marked cup graduated in milliliters is the only reliable way.
Why is the American teaspoon not a round number?
Because it is a sixth of a US fluid ounce, and the fluid ounce comes from the gallon rather than from the liter. Every American kitchen measure inherits that decimal tail, which is why the teaspoon, the tablespoon and the cup all end in long fractions.