Converting Teaspoons to Milliliters (tsp to mL) is critical for both baking and medicine. While many people round a teaspoon up to 5 mL, the precise US teaspoon is roughly 4.93 mL. This difference is negligible in a cup of tea, but in medicine or chemical recipes, precision matters. Understanding this conversion helps you use standard oral syringes or metric measuring cups when a teaspoon is not available.
Master Volume Converter
The Formula
Multiply the Teaspoons by 4.929:
tsp × 4.929 = mL
Example
A dose of medicine is 2 tsp:
2 × 4.929 = 9.86 mL
Culinary & Health Volume Insights
In both modern medicine and metric cooking, a teaspoon is defined as exactly 5 ml. While the historical US Customary teaspoon is 4.92892 ml, the 5 ml standard is used on all modern measuring spoons and medicine droppers to ensure safety and consistency.
Frequently Asked Questions
One US customary teaspoon is equivalent to 4.92892159 milliliters. However, the legal definition used for food labeling in the US and the standard for metric teaspoons in the UK and Canada is exactly 5 ml. For almost all household purposes, the 5 ml value is the correct one to use.
“Small” spoons used for coffee or tea in a standard cutlery set can vary in volume from 3 ml to 7 ml. When measuring potent ingredients like baking soda or liquid medications, this variation can lead to failed recipes or incorrect dosages. A calibrated measuring spoon ensures you hit that 5 ml mark every time.
If you don’t have a calculator, just multiply by 5. If a recipe calls for 4 teaspoons of an extract, 4 times 5 is 20 ml. This mental shortcut is the standard for chefs, bakers, and parents measuring out supplements or medicine.