I don't measure it but probably about 10-20%. I mix it 50% for the spray bottle and use it around the shop. This is by far the best general purpose cleaner that I have found. It will clean circles around Simple Green and that other purple stuff. Also it is pretty easy on paint; I use it to clean my Machine tools with out any problems.This is what I use in my small ultrasonic cleaner and have had great results with it.