I carry this with me every day. Albeit, too big, made of plastic, and not a great top that I always take off, it is a trustworthy 64 ounces that I try to fill twice per day with our trusty Brita Filter Pitcher. I usually struggle to finish the second one. I've heard all kinds of advice about how much water to drink per day, but I tell my Health Coaching clients to drink until you pee clear. Then, you are hydrated.