Depends on 2 things. Size of slin pin (1/2cc or 1cc) and how much BW you use to reconstitute it with. Or ar you using the water that comes with the kits??? If all you're doing is 2iu's a day then you better use BW.

I reconstitute my 18iu vials with 1.8mL of BW. That way ever "10" on a 1inch Slin pin is 1 iu. Can't make it any easier then that.......