½ tsp to milliliters.
½ US teaspoon = 2.46 mL. On US food labels, 1 tsp means exactly 5 mL, so ½ tsp is 2.5 mL there.
What ½ tsp means
- At the 5 mL food-label size, ½ tsp is 2.5 mL: half a teaspoon (½ tsp).
- ½ tsp is 0.17 US tablespoons and 0.083 US fluid ounces.
- A ½ tsp mark and a 2.5 mL mark are the same dose on a label.
- A US customary teaspoon is exactly 4.92892159375 mL. US food labels round it to 5 mL, a difference of 1.4 %.
Measuring a 2.5 mL dose
- Dose liquid medicine in mL only. The American Academy of Pediatrics recommends doses to the nearest 0.1, 0.5 or 1 mL, measured with an oral syringe.
- Draw the syringe to the 2.5 mL line. Use the device that comes with the medicine, or one from a pharmacy.
- In a study of parents of young children, those using teaspoon or tablespoon units had about twice the odds of a dosing error as those using mL only.
- The FDA and US pharmacy standards bodies recommend mL as the only unit on prescription labels for oral liquids.
How to convert
- Multiply by 4.92892159375 (the exact mL in one US teaspoon): 0.5 × 4.9289 = 2.46 mL.
- For the food-label teaspoon, multiply by 5: 0.5 × 5 = 2.5 mL.
To convert the other way, use the milliliters to US teaspoons converter.
Nearby values
| US tsp | mL (US 4.93 mL tsp) | mL (5 mL label tsp) |
|---|---|---|
| ¼ tsp | 1.23 | 1.25 |
| ½ tsp | 2.46 | 2.50 |
| ¾ tsp | 3.70 | 3.75 |
| 1 tsp | 4.93 | 5.00 |
| 1¼ tsp | 6.16 | 6.25 |
| 1½ tsp | 7.39 | 7.50 |
| 1¾ tsp | 8.63 | 8.75 |
Questions people ask
Is ½ tsp a teaspoon or a tablespoon?
At the 5 mL label size, 2.5 mL is half a teaspoon (½ tsp). One tablespoon is 15 mL, or 3 teaspoons.
Can I measure a ½ tsp dose of medicine with a kitchen spoon?
For medicine, use the cup, syringe or dropper that comes with it. The FDA says a kitchen spoon could hold the wrong amount. Use an oral syringe or a dosing cup marked in mL, filled to the 2.5 mL line.
Sources: NIST Handbook 44, Appendix C (US gallon, quart, pint, cup, fluid ounce, tablespoon and teaspoon); 21 CFR 101.9(b)(5)(viii) (FDA nutrition labeling: 1 tsp = 5 mL, 1 tbsp = 15 mL); FDA Consumer Update: Ten Tips to Prevent an Accidental Overdose; FDA-hosted guidance on mL-only dosing for oral liquid medicines; American Academy of Pediatrics, Metric Units and the Preferred Dosing of Orally Administered Liquid Medications, Pediatrics 2015;135(4):784–787; Yin HS et al., Unit of measurement used and parent medication dosing errors, Pediatrics 2014;134(2):e354–e361.
Sources & verification
Unit definitions used by this converter:
- teaspoon (US): 1 tsp (US) = 0.00492892159375 L, exact (tsp = 1/3 tbsp) — NIST Handbook 44 (2026), Appendix C
- milliliter: 1 mL = 0.001 L, exact — BIPM SI Brochure, 9th ed.