I notcied a lot of the generic brands of bleach you find in grocery stores don't always list the percentage of sodium hypochlorite anywhere on the lable. Here's a list of bleaches and their % that I found which included my local store's brand (Jewel bleach). I have no idea if this is an all inclusive list, but I though it might be helpful for people trying to find the correct value to plug into Michael's BleachCalc formula.

Bleach brand list

Bill