I'm planning on finding a bag for school online and need a general idea of what kind of size I will need.

I probably need to fit a 4 inch binder in the bag as well as one or two paper back books and a text book weighing 4lbs and measuring 11 x 8.5 inches. My bag must be able to handle this.

I'm not looking for a logo tote and I'm not limited to totes.

Basically, I want a general suggestion of the size of bag I should use and perhaps a few examples.