JimmyYimmyFanThe inner dimensions are about the length of a US paper note, I don't have a ruler, but putting a dollar in the inside of the ear cup is almost exact, so based on google about 2.6 inches, or 6.6 centimeters, or .0000410354 miles.
JimmyYimmyFanWith my tape measure it just about 2 and half inches, so asdfman is on the money. (BTW I assume is talking about a dollar bill folded in half).
Even if you ear touches a little, it shouldn't be a problem. The ear pads are very soft comfy.