Quarts (US liquid) to milliliters conversion calculator shown above calculates how many milliliters are in 'X' quarts (US liquid) (where 'X' is the number of quarts (US liquid) to convert to milliliters). In order to convert a value from quarts (US liquid) to milliliters (from qt to mL) type the number of qt to be converted to mL and then click on the 'convert' button.