tsp to mL Converter
Turn teaspoons into milliliters in one step. Enter an amount and pick your teaspoon standard — US customary (4.92892 mL), metric (5 mL), or UK/Imperial (5.91939 mL) — to get mL, tablespoons, and fluid ounces.
Example: with Teaspoons (tsp) 2 · Teaspoon standard US customary (4.92892 mL) → Milliliters: 9.86 mL.
- In tablespoons0.667 tbsp
- In fluid ounces (US)0.333 fl oz
Computed by the calculator below using its default values. Change any input to see your own numbers.
1 US teaspoon = 4.92892 mL (NIST). Three US teaspoons make one tablespoon, so 3 tsp is almost exactly 14.79 mL.
Why a teaspoon is not always 5 mL
Recipes and medicine labels use different teaspoons. The US customary teaspoon is defined as exactly 4.92892 mL, but the metric teaspoon used across Europe and Australia is rounded to a clean 5 mL, and the older UK Imperial teaspoon is larger at 5.91939 mL. The gaps are small for one spoon but add up when a recipe calls for several.
For cooking, the difference between 4.93 and 5 mL almost never matters. For medicine dosing it can, which is why pharmacists prefer an oral syringe marked in milliliters over a kitchen teaspoon.
How it’s calculated
Milliliters = teaspoons × the mL value of the chosen standard: US 4.92892 mL, metric 5 mL, UK/Imperial 5.91939 mL (NIST). Tablespoons = mL ÷ 14.7868; US fluid ounces = mL ÷ 29.5735.
Assumes level teaspoons of liquid. A heaping spoon or a dry ingredient that mounds will hold more volume than the flat measure.
Common teaspoon amounts (US standard)
| Teaspoons | Milliliters | Also equals |
|---|---|---|
| 1/4 tsp | 1.23 mL | a pinch |
| 1/2 tsp | 2.46 mL | — |
| 1 tsp | 4.93 mL | 1/3 tbsp |
| 2 tsp | 9.86 mL | 2/3 tbsp |
| 3 tsp | 14.79 mL | 1 tbsp |
| 6 tsp | 29.57 mL | 1 fl oz |
Computed as teaspoons × 4.92892 mL (US customary, NIST); rounded to two decimals.
Common mistakes
- Mixing standards — a metric 5 mL teaspoon is about 1.5% larger than the US 4.93 mL one.
- Using a heaping spoon for a level measurement, which can add 50% or more for powders.
- Assuming a kitchen teaspoon equals a labeled medicine dose; use an oral syringe for medicine.
Frequently asked questions
How many mL is one teaspoon?
One US customary teaspoon is 4.92892 mL, usually rounded to 5 mL. The metric teaspoon is exactly 5 mL and the UK Imperial teaspoon is 5.91939 mL.
What is the formula for tsp to mL?
Multiply teaspoons by the mL value of your standard: 4.92892 for US, 5 for metric, 5.91939 for UK. So 2 US tsp = 2 × 4.92892 = 9.86 mL.
Is a teaspoon 5 mL or 4.93 mL?
Both are used. The metric teaspoon is a clean 5 mL; the US customary teaspoon is 4.92892 mL. The difference is tiny in cooking but can matter for medicine.
How many teaspoons are in a tablespoon?
Three. One US tablespoon is 14.7868 mL, which is exactly three US teaspoons of 4.92892 mL each.