The numbers on the bottom don't necessarily relate to the size. You measure the skillet across the top (not including the pouring bumps if they have them) to get the size. A #8 Lodge skillet is about 10 1/4 inches across the top. I would call this a 10 inch skillet.

And a #3 Wagner Ware cast iron skillet is considered a 6-inch skillet (measured across the top). The number 3 is on the handle as you are looking into the skillet. I'm looking for a Wagner Ware #6 skillet because I love my #3 so much!

Teresa