Standard Chlorox bleach was always 5.25%, about 2 years ago they came out with Ultra as a way to rip off the consumer. You see the difference between regular and ultra is that ultra is 6% but it comes in a smaller bottle. The ultra bleach is not sold in a gallon bottle but in one that smaller, forget exact size. The two generally sell for the same price, but if you calculate how much of the active you are actually getting the 5.25% bottle is normally cheaper.