How long will it take for my hair to grow out?

When i was younger i had really long hair, up to my hips. Then last year i cut my hair really short, like up to my shoulders. Then, i decided i wanted to grow my hair out again. Just one problem, i would always straighten my hair, which damaged it alot. I stopped straightening my hair and bought hair products to help repair my hair. Now, my hair looks a lot healthier, but it's still short (alittle below my shoulders). I had just bought nexus split end repair cream. It says to put it in before you go to bed, so i'll see results tomorrow morning. So if i keep my hair in good condition and use the nexus cream, how long will it take for my hair to grow under my chest? Will it help it grow faster at all?