Is my treadmill in miles or kilometers?

I am in China as a foreign exchange student. My family has a treadmill. I have been running (I had to buy new shoes first as they don't let out door shoes like my running shoes inside). But I've been maxing the machine out at 12 and holding that pace for 16 minutes doing 3 units of distance at that pace. I know I can run sub six minute miles (or I have back in America). I did some math and if it is kilometers it means the machine maxes out at like 8:15 minute miles which seems very slow for a treadmill. My American one goes down to 5:30. Any ideas?