Is the song think of me for soprano or mezzo?

Okay, so i've been wanting to know if i'm a mezzo soprano or a soprano, my voica ranges from F3-C6, and i can comfortably sing up to F#5 and sometimes G5, and when i sing songs like Pie Jesu(which hits an Ab5 about 6 times) it sounds insecure, and i dont feel completely strained. BUt when i sing songs like for mezzosopranos i feel comfortable, but i feel like i can sing higher, and ame when i sing songs from contraltos. However i can sing Think of me from phantom of the opera completely comfortable. Why is this? Am i a mezzo or a scared-of-high-notes Soprano?