you will need to actually CC your chambers, and piston dome volumes. You will also have to know your deck height and calculate the CC's for that too. Your gasket CC's you should be able to get that from your gasket manu.
Then you will punch those numbers into the formula and that will give you your CR not a guess...but your actual CR.
BUT the only way to get that is to measure and get the actual CC's of the items listed...