Im 16 years old, when is my voice going to deepen?

im tired of my little boy voice.and sometimes I speak and I feel & hear my voice sounding diffrent, deeper,but then it changes back to where it is..will it change when im older?

It doesn't change all at once. It will flip back and forth between tenor aqnd bass mode for a while and finally stay in bass. What you describe sounds like it's beginning the process now.