Not very big, but we use it as a day bag for my 9 month old. It is a Toddler Backpack for daycare or pre-K. It holds 4-10 diapers (depending on size), a pop up pouch of wipes, a bottle or two, 3 pacis, and a few small toys AT MOST.  This should not be used as a diaper bag if your child needs more than that in a day.

But its just the cutest darn thing!  I get a ton of compliments on it.  Well made, durable, washes easy with a clean cloth and soap and water. No washing machine.