Teaspoons (US) to milliliters converter on this page calculates how many milliliters are in 'X' teaspoons (US) (where 'X' is the number of teaspoons (US) to convert to milliliters). In order to convert a value from teaspoons (US) to milliliters (from tsp to mL) simply type the number of tsp to be converted to mL and then click on the 'convert' button.