Teaspoons to Milliliters Converter
Teaspoons are small, familiar, and easy to write in recipes. Milliliters are clearer for scaling, labeling, and metric measuring tools. This calculator starts from a US teaspoon amount and converts it to milliliters using the factor built into the calculator: 1 tsp = 4.92892159375 mL. It can also run the reverse direction, but the guidance here is teaspoon-first.
The default value is 3 teaspoons, which is a common kitchen bridge because 3 US teaspoons equal 1 US tablespoon. With the exact US teaspoon factor, 3 teaspoons equal 14.78676 mL, displayed as 14.79 mL. That is close to the familiar 15 mL metric tablespoon, but it is not the same number.
Teaspoon-first situations
Use this page when the recipe or instruction begins with teaspoons: 1 tsp vanilla, 2 tsp oil, 0.5 tsp extract, or 3 tsp vinegar. Converting to milliliters helps when you want to scale a recipe, enter a value in a nutrition app, use a syringe or beaker, or compare with a metric source. If the source already gives milliliters, the ml to tsp converter presents the inverse workflow more directly.
This calculator is about volume only. It does not turn teaspoons into grams. A teaspoon of water and a teaspoon of table salt have the same volume but very different masses. For mass-to-spoon estimates, use the g to tsp converter. For spoon-to-mass estimates with tablespoons, use the tbsp to grams converter.
Formula
For US teaspoons to milliliters:
For the reverse direction:
For metric teaspoon comparison:
The metric comparison is included because many sources round one teaspoon to 5 mL. The calculator keeps the US computation and the metric comparison separate.
Worked example
The default value is 3 in US teaspoons to milliliters mode.
The primary result is 14.79 mL after display rounding. The result details show the US teaspoon factor as 4.92892159375 mL per tsp and the metric teaspoon factor as 5.00 mL per tsp. The metric-teaspoon comparison is:
The calculator displays that comparison with up to four decimals, so it appears as 2.9574 metric tsp.
Reference table
| US teaspoons | Milliliters | Metric teaspoon equivalent | Common kitchen label |
|---|---|---|---|
| 0.25 tsp | 1.23 mL | 0.2465 metric tsp | One-quarter teaspoon |
| 0.5 tsp | 2.46 mL | 0.4929 metric tsp | One-half teaspoon |
| 1 tsp | 4.93 mL | 0.9858 metric tsp | One teaspoon |
| 2 tsp | 9.86 mL | 1.9716 metric tsp | Two teaspoons |
| 3 tsp | 14.79 mL | 2.9574 metric tsp | One US tablespoon |
| 4 tsp | 19.72 mL | 3.9431 metric tsp | One tbsp plus one tsp |
| 6 tsp | 29.57 mL | 5.9147 metric tsp | Two US tablespoons |
The table also shows why “1 teaspoon = 5 mL” is a convenient approximation. For one spoon, the difference is only about 0.07108 mL. For 6 teaspoons, the gap from a 5 mL metric shortcut becomes about 0.43 mL.
Cooking context and pitfalls
Teaspoons work well for flavorings, leaveners, spices, oil, vinegar, and other small volumes. They are less reliable when the ingredient is sticky, foamy, heaped, or measured with a household dining spoon. A level measuring spoon is the assumed volume. A rounded spoon can hold far more, especially for powders and pastes.
Keep the unit standard attached to your recipe notes. If you convert 2 teaspoons to 9.86 mL, write that exact value before scaling. If you round it to 10 mL and later multiply by 12 batches, the rounding becomes larger than it looked at the start. For formulas, labels, or small concentrated amounts, a milliliter-marked tool is better than trying to eyeball fractional teaspoons.
For larger volumes, move from teaspoons to tablespoons or cups. The ml to tbsp converter helps when a milliliter value is better expressed as tablespoons, and the volume converter handles cups, liters, fluid ounces, and other units.
Keeping teaspoon notes readable
A teaspoon result is most useful when it is converted into a measurement someone can repeat. Instead of writing a long decimal into a family recipe, keep the milliliter value and add a sensible spoon note. For example, 7.39 mL can be noted as “about 1.5 US tsp” for a sauce, while a precise formula should keep 7.39 mL. The conversion factor tells you the exact relationship; the recipe context tells you whether rounding is acceptable.
When you compare recipes from different countries, identify the spoon standard before adjusting flavorings or leaveners. A metric recipe that says 5 mL may be calling for one metric teaspoon. A US recipe that says 1 teaspoon is slightly less at 4.92892159375 mL. The difference rarely ruins dinner, but preserving it in documentation makes scaled batches and nutrition notes more defensible.
Sources
- NIST, SI Units — metric unit context for milliliter-based measurement.
- NIST, Unit Conversion — general conversion-factor guidance.
- USDA FoodData Central, food composition database — ingredient data source for cases where volume later needs mass.