How long does my hair have to be to start dreads?

Well that all depends on how much work you want to put into your dread locks, if you start your dreads with 2 inches of hair, then you will be putting a lot of work into them but they won’t really look like dreads. If you start your dreads with 5 or 6 inches of hair then you will have a much easier and rewarding experience with making dread locks.