One molar contains 1,000 millimolars. You can convert molar to millimolar by multiplying the figure by 1,000. In the metric system, the prefix "milli-" represents 10 to the power of -3, or one one-thousandth.
Molar concentration, or molarity, is a scientific measurement that describes the concentration of a solution. It measures the number of moles of a solute in a liter of a solution. To calculate molarity, start with the number of moles of solute present. To determine this number, use the periodic table to find molar masses. Divide this by the volume of the solution to get the answer.