Confirm the conversion rate of a cubic foot to one liter is 28.31685. This means that for 1 cubic foot, you have 28.31685 liters.
Multiply 28.31685 by 1,000 to convert liters to milliliters. There are 1,000 milliliters in every liter, so for every cubic foot there are 28,316.85 milliliters.
Determine the conversion rate for your problem using simple multiplication. For example, if converting 5 cubic feet, then 28,316.85 multiplied by 5 equals 141,584.25 milliliters.