There should be a chart on the gauge showing what the % of breaking point is for the diameter wire being tuned. I know on my boat the shrouds and back stay are 5/16 in dia. and the mid stays are 1/4 in dia. Follow the instructions on how to install the gauge on the wire and using the chart for reference the 5/16 shrouds should be tuned to 12% on the gauge and the 1/4 mid stays 9 to 10% now keep in mind you will be going back and forth between stays and shrouds eying up the mast for straightness. Once this is achieved go out and sail to see if its to your satisfaction you might have to fine tune and adjust! It is a process and be prepared to spend some time with it! But in the end your rig will be properly tuned. Hope this helps.