How can I know if I can sing good or not?

I've have been singing for a while and everyone thinks I sing good but I just think they are being polite how can I find out if I can really sing or not?

video tape yourself. or try out for american idol. or go to a vocal coach.

If the Mirror doesn't Break..

Small joke.

Um...I'd say you should Record yourself and see whether is sounds good or not.

thanks I liked your joke very cute!

record yourself
thats what I did
turns out I suck but maybe you dont
and have someone else you dont know at all
opinate it