Depends on the strength you are using...we get the 13.3%. I believe there is a 10% strength also. We mix ours in a 32 oz plastic sprayer and we use less than an ounce per sprayer full. I've been reading up on how to treat clothing and I've found that many people use the 10% diluted to 0.50% which is 6.4 oz per gallon. That sounds strong, but I guess if we were making it by the gallon we would be using just under 4 oz.