Convert teaspoon to ml

Teaspoon (U.S.)

Definition
A U.S. customary teaspoon (tsp) is a volume measure equal to 4.9289215938 mL. The “metric teaspoon” used in many nutrition labels and recipes is standardized at 5 mL.

History & Origin
In the 18th-century Apothecaries’ system, the teaspoon equaled 1 fluid dram, ¼ tablespoon, or ⅛ fluid ounce. Early teacups and spoons were small—reflecting the high cost of tea—so a teaspoon then was smaller than today’s. As tea became affordable in the early 1700s, spoons grew to ⅓ tablespoon, matching the current size ratio.

Modern Use
Teaspoons measure small volumes in cooking (especially baking) and dispense medication. Outside kitchens and pharmacies, metric units like milliliters or liters prevail for volume.

Milliliter

Definition
A milliliter (mL) is the metric volume unit equal to 1 cubic centimeter (1 cm³), 0.001 liters, or 1 × 10⁻⁶ m³.

History & Origin
The milliliter derives from the liter (originally litre in French), once defined by water’s mass. Today it simply reflects the “milli-” prefix—one-thousandth of a cubic decimeter.

Modern Use
Milliliters are ubiquitous for small-volume needs: lab solutions, medicine syringes, condiment bottles, travel toiletries, and nutritional labeling. Precision instruments (pipettes, graduated cylinders) rely on mL graduations.

Teaspoon → Milliliter Conversion Table

How to Convert

• 1 tsp US = 4.9289215938 mL

• 1 mL ≈ 0.2028841362 tsp US

Example

Convert 15 tsp US to milliliters:

15 tsp × 4.9289215938 mL/tsp = 73.9338239063 mL