How long will dreadlocks be with 5 inches of straight hair?

I started mine at around 4 inches and now they are at 5.... thinking i might back comb. Either that or pull and twist method. If you start at 5 inches and back comb they will be little stubs. If you do the twist and pull method with beeswax and use elastics... they will almost be about the same size just a little shorter