It's hard to answer your question, as it is hard to tell if you want to wind a transformer secondary of if you just want an inductor. The formula for winding an inductance is here - http://www.allaboutcircuits.com/vol_5/chpt_1/6.html.
If it's a transformer, the ratio of primary turns to the secondary turns gives the output voltage. If you can't get at the primary, you may have to wind the secondary experimentally - put on some turns, apply power, and use a meter to check the secondary voltage. Add or subtract turns until the voltage is correct.
thanks man
but i need it to be used as electro magnet but i need to have it on the a PVC with air core nothing in the middle just empty. will that formula works?
still i don't see how to relate voltage and number of turns with the dimentions of the pvc.
Yes, the first two formulae will work for air core. Just substitute mu_r = 1 .
Be aware that the rest of the formulae assume that the inductor is circular, but your inductor is rectangular.