How many ml in 1 cm?

There is no direct conversion between milliliters (mL) and centimeters (cm) as they measure different things (volume and length, respectively). However, if you are referring to the volume of a cube with sides measuring 1 cm, then the volume would be 1 cubic centimeter (1 cm^3), which is equal to 1 milliliter (1 mL) of water.