I want to make some coconut macaroons and my recipe calls for 5 cups of unsweetened coconut and 2.5 cups of sugar. I have sweetened coconut but not unsweetened and don't feel like going out. I know I've figured this out before but didn't write down my substitution and am having trouble finding it now. The bag of sweetened says that 2 Tbs has 5 g of sugar, and I found online that unsweetened has less than 1 g sugar in 3 Tbs. (so I'll assume zero to be simple) With that I figured that 5 cups of sweetened contains 40x5=200 g of sugar or about a cup, meaning I'd reduce the added sugar to 1.5 cups. Sound reasonable? I saw a lot of "advice" on the web about "reducing sugar by a tablespoon or two per cup" but don't know how informed that advice is.
(Yeah I know there are some volume issues in that I actually have less than 5 cups of coconut now, but coconut is pretty "fluffy" so I'd be inclined not to worry about it too much; maybe just reduce other things a bit)