This is the wonderful tool from Mathias Gemuh, the author of ChessGUI/BigLion.
The purpose of this tool is to determine the rating in CCRL 40/4 scale given Total Scores as Input.
You need to give the STS 1-10 Total Score as input and then click Calculate.
It gives valuable info as to how much the particular version of the engine has improved over the previous version, or a rough elo-estimate of any new engines.