How much is a millileter?

Answer 1

1 millilitre is 1000 micro-litres or 1/1000 of a litre. If you are cooking, to approximate, take a scant 1/4 teaspoon.
It's a cubic centimeter ...

or about a fifth of a tea-spoon.

Answer 2

You can measure a millimeter in many ways. You could say that a 10 millimeters equals one centimeter or you could say that a millimeter is smaller than the dot of an i in a 8 point font.