ugh.... i want to check the measurements on some recipes and was using gourmetsleuth's calculator but found there weren't some ingredients listed, like tapioca flour/starch. i also tried googling, but didn't find results. i know we can look up the substitute ingredient online, so... can we use the substitute ingredient if it has a 1:1 ratio to find the correct measurement? or is that waaay off? sorry if that sounds dumb, but what a pain it is that we don't all use the same measurement system...
As chefj said, it is easier to just list what ingredient (and the amount of such) with what you wish to substitute it with, *or* note if the problem is between differing types of measurements.
If conversion between systems is a problem, this might help: http://www.realfood4realpeople.com/co...
For tapioca flour specifically, this link from Cook's Thesaurus might help: http://www.foodsubs.com/ThickenStarch...
And you can thank my good old US of A for refusing to go metric :( It drives me crazy(er) for more than just cooking.