Volume conversion
US teaspoon to Milliliter converter
Convert tsp to mL instantly, choose the displayed precision, and verify the result with the formula and reference table below.
Milliliter (mL)
Rounded for display only; calculations retain full precision.
Rounding and precision rules
- Convr calculates first and rounds the displayed result only once, at the final step.
- The default is a maximum of 6 decimal places; trailing zeros are removed.
- Very small values that would appear as zero, and values of 10¹² or more, use scientific notation.
- Display precision is not measurement uncertainty. For scientific, engineering, or regulated work, retain only the digits justified by the source measurement.
Practical context
Understanding this conversion
US teaspoons measure small ingredient, flavoring, and serving quantities. Milliliters are better suited to metric recipes and precise liquid measurement.
The conversion distinguishes a standardized US customary teaspoon from the variable capacity of an ordinary spoon. Use the exact factor when accuracy or recipe scaling matters.
Reviewed August 16, 2026.
Calculation
US teaspoon to Milliliter formula
mL = tsp × 4.928922
Calculations retain full precision and the result is rounded only for display.
Worked example
For 10 tsp, the result is 49.289216 mL. Substitute 10 tsp into the formula to obtain 49.289216 mL.
A numerical value expressed in milliliter is usually larger than the same measurement expressed in us teaspoon, because 1 tsp equals 4.928922 mL.
US teaspoon to Milliliter reference table
Common values rounded to a maximum of 6 decimal places.
| US teaspoon (tsp) | Milliliter (mL) |
|---|---|
| 1 tsp | 4.928922 mL |
| 5 tsp | 24.644608 mL |
| 10 tsp | 49.289216 mL |
| 50 tsp | 246.44608 mL |
| 100 tsp | 492.892159 mL |
Understanding the units
About US teaspoon and Milliliter
US teaspoon (tsp)
One us teaspoon (tsp) equals 0.004928922 L, the base relationship used for this volume conversion.
Milliliter (mL)
One milliliter (mL) equals 0.001 L, the base relationship used for this volume conversion.
When this conversion is useful
US teaspoon to Milliliter conversion is useful for recipes, beverage quantities, fuel volumes, laboratory measurements, and container capacities. It lets you compare the same volume or capacity across documents, tools, or standards that use different units.
Learn with Convr
Conversion guides
Metric vs Imperial Units: A Practical Comparison
Understand how metric, US customary, and Imperial units differ, where each system is used, and how to convert between them reliably.
Read guide →Everyday conversionsUS Gallons vs Imperial Gallons: What Is the Difference?
Compare US liquid gallons and Imperial gallons, understand their exact liter values, and avoid common fuel and recipe conversion errors.
Read guide →Answers at a glance
Frequently asked questions
How many milliliters are in one US teaspoon?
One US customary teaspoon equals exactly 4.92892159375 milliliters.
Why do recipes often say one teaspoon is 5 mL?
Five milliliters is a convenient metric kitchen approximation. It is close to, but not identical with, the US customary teaspoon.
How does Convr round US teaspoon to Milliliter results?
Convr keeps full numeric precision during the calculation and rounds only the displayed result. The default is a maximum of 6 decimal places, with selectable precision on this page.
Can I convert negative or decimal us teaspoon values?
Yes. The converter accepts positive, negative, decimal, and scientific-notation values. Negative values are physically meaningful for some scales, such as temperature, but not for every measured quantity.
Keep converting