I have an old crib. How can I turn it into a toddler bed.
First, decide what size mattress you are going to use. Then build a frame and attach the head and foot of the crib to the frame.
Keep in mind that kids grow really fast so you may want to make it at least sofa high so they can use it longer.
How old is 'old'? What material is the crib made out of - metal, wood?
Posting a picture would be helpful to see what you are starting with.