We bought our first smaller bag of Nutro Complete Care Weight Management Formula and it lastest not quite a month, I was mixing ($7.00 a bag) now we got 20 lbs bag and it's about $26.00 a bag at PetSmart, I think. We just opened the bag a few days ago. This may only last a month since I'm not mixing it with anything else. Love the shape of this stuff looks like mini footballs.