Take a sheet of typing paper. Run it through a desktop printer, and print a single period on it.
That spot represents, fairly accurately, the proportion of ANWR's 19.16 million acres that would be allowed for development.
As I recall, the common comparison is to note that the parking lot at JFK airport covers roughly as much land as would be allowed to be developed in ANWR. And that's out of an area 20% larger than the entire state of West Virginia, which is itself located in a state that has almost a sixth of all the landmass in the entire United States.
Also keep in mind that Congress specifically set aside 1.5 million acres of the Costal Plain (the northern edge of ANWR) for oil and gas exploration. If you wish to pick nits, this are is legally neither "refuge" nor even "wilderness", but that's just semantics.
