solubility logS - logS of what? (comparison with uM?)

According to

https://docs.chemaxon.com/display/CALCPLUGS/Solubility+Predictor

one can calculate either

mg/ml | mol/l | logS

So when using logS, from which result is it taken? of mg/ml or mol/l? 

Or to ask in different way: I have experimental solubility data in micromolar. How do I compare that to the calculated Chemaxon solubility?

Dear Alexander, 

logS is a unit of expressing solubility in itself, which is the 10-based logarithm of the solubility measured in mol/l. So you can calculate the solubility in three units: logS, mol/l, and mg/ml.

To calculate our data in micromolar simply calculate the solubility in mol/l, and then multiply it by 10^6.

We have updated our documentation page with the definition of the logS unit.

BR, 

Daniel

Thanks!