it pretty much matters who is dealin to u when it comes to how much weight u'll get from certain sacks but to try and make it easy an ounce is 30 grams a quarter is usually anywhere from 7-10 grams a dub would usually be about 1-2 grams so on and so forth most dealers i know will do .3 grams for 5 bux and then .4 for the next 5 like if u give em 20 they'll give you 1.3 you give em 25 they'll give u 1.7 give em 30 theyll give u 2 so on so forth