Yes it is pretty much normal. if you are worried about penis size you can research more over the net. you still have a lot of time for penile development so dont worry.
If your penis is larger erect than your two fingers pointing out, the index and middle finger, then you're on the right track for average...anything more is a bonus.
It only has two factors.
It is: 7/13 times 100/1 = 53.85% rounded to two decimal places
13Is any among you afflicted? let him pray. Is any merry? let him sing psalms. 14Is any sick among you? let him call for the elders of the church; and let them pray over him, anointing him with oil in the name of the Lord: 15And the prayer of faith shall save the sick, and the Lord shall raise him up; and if he have committed sins, they shall be forgiven him. 16Confess your faults one to another, and pray one for another, that ye may be healed. The effectual fervent prayer of a righteous man availeth much.