US teaspoons to Millilitres
1 US teaspoon = 4.9289 millilitres · 1 mL = 0.20288 tsp (US)
1 US teaspoon = 4.9289 millilitres
How it’s calculated
mL = tsp (US) × 4.928921594
- Multiply the value in US teaspoons by 4.928921594.
- To go back, divide by 4.928921594 (or multiply by 0.2028841362).
- 1 tsp (US) = 4.928921594 mL · 1 mL = 0.2028841362 tsp (US)
Show worked solutionFactor, unit cancellation and rounding, step by step
Find the conversion factor
By definition 1 tsp (US) = 0.00000492892159375 m³ and 1 mL = 0.000001 m³, so 1 tsp (US) = 4.92892159375 mL. Source: NIST SP 811 / Handbook 44; BIPM SI Brochure (9th ed.).
Multiply by the factor written as a fraction
Put tsp (US) in the denominator so it cancels, leaving mL.
Calculate (unrounded)
Round the answer
Rounded to 5 significant figures.
Answer: 4.9289 mL
1 tsp (US) in other units
Batch convert tsp (US) → mL
- 1 tsp (US) = 4.9289 mL
- 5 tsp (US) = 24.645 mL
- 10 tsp (US) = 49.289 mL
- 25 tsp (US) = 123.22 mL
Quick examples
- 1 US teaspoon = 4.9289 millilitres
- 5 US teaspoons = 24.645 millilitres
- 10 US teaspoons = 49.289 millilitres
- 25 US teaspoons = 123.22 millilitres
- 100 US teaspoons = 492.89 millilitres
About these units
US teaspoon (tsp (US))
US customary
1/3 US tablespoon = 4.928 921 593 75 mL.
1 tsp (US) = 0.000004928921594 m³
Source: NIST SP 811 / Handbook 44
Millilitre (mL)
metric (non-SI)
Exactly 1 cm³. Also written cc.
1 mL = 0.000001 m³
Source: BIPM SI Brochure (9th ed.)
US teaspoons to millilitres conversion table
| US teaspoons (tsp (US)) | Millilitres (mL) |
|---|---|
| 0.125 tsp (US) | 0.61612 mL |
| 0.25 tsp (US) | 1.2322 mL |
| 0.3333333333 tsp (US) | 1.643 mL |
| 0.5 tsp (US) | 2.4645 mL |
| 0.6666666667 tsp (US) | 3.2859 mL |
| 0.75 tsp (US) | 3.6967 mL |
| 1 tsp (US) | 4.9289 mL |
| 1.5 tsp (US) | 7.3934 mL |
| 2 tsp (US) | 9.8578 mL |
| 3 tsp (US) | 14.787 mL |
| 4 tsp (US) | 19.716 mL |
| 5 tsp (US) | 24.645 mL |
| 6 tsp (US) | 29.574 mL |
| 8 tsp (US) | 39.431 mL |
Related conversions
Frequently asked questions
How do I convert US teaspoons to millilitres?
Use mL = tsp (US) × 4.928921594. Multiply the value in US teaspoons by 4.928921594.
How many millilitres are in 1 US teaspoon?
1 US teaspoon (tsp (US)) equals 4.9289 millilitres (mL); more precisely 4.928921594.
How many US teaspoons are in 1 millilitre?
1 millilitre (mL) equals 0.20288 US teaspoons (tsp (US)); more precisely 0.2028841362.
What is 10 tsp (US) in mL?
10 US teaspoons = 49.289 millilitres.
Is the US teaspoon a US or a UK unit?
This converter uses the US customary US teaspoon. 1/3 US tablespoon = 4.928 921 593 75 mL. US and UK units with the same name can differ, so check which one your source uses.
What is a US teaspoon?
1/3 US tablespoon = 4.928 921 593 75 mL.
What is a millilitre?
Exactly 1 cm³. Also written cc.
Formula: mL = tsp (US) × 4.928921594. Factors last reviewed 2026-10-27.