if they are the tinyest piercings, like if you got them from walmart or claires, then its a 22. If you got them done at a tatoo/piercing parlor they are most likely a 16. 14 is usually the standard size for facial piercings, and a 16 or 18 is standard ear sizes... I know ppl who have gotten their ears done with a 10 though, so its all on preference and what size the piercer used.
Im sure you could force a 16 or 18 in if you had too, it may hurt for a few days, but its not too bad