I get that the recent changes calculator target/efficiency section are aimed at better accuracy. I know that a lot of thought and effort went into it. I also know that it's caused a hell of a lot of confusion and frustration. One reason for this is that when toggling between Fermenter and Kettle for target, different parameters are being used to derive resulting attributes. When using the Fermenter as target, changes boil time change everything. When Kettle is target, different boil times change nothing. When using Fermenter, changes in batch size change nothing unless the batch size is smaller than the pre-boil. When using Kettle, batch size changes everything, regardless of pre-boil size and changes in pre-boil change only IBUs. Pre-boil remains a user-input no matter what. Wouldn't it be simpler just to use the equipment profile boil-off to calculate pre-boil as well as using system losses to account for differences in kettle and fermenter calculations? Just make batch size the only user input and get the rest of the data from the boil-off, boil time, estimated efficiency and equipment losses. When a brewer has a limit on kettle capacity, they use kettle as a target if they need to max out and whatever goes into the fermenter is the same as what comes out of the kettle in all aspects other than volume. When fermenter capacity is the limiting factor, that target should be used so that there's no wasted wort. When the user-input batch size and boil time indicates that the pre-boil volume exceeds capacity listed in equipment profile, an error message should pop up. I doubt that making the change from user-input to forumula-derived for pre-boil volume would solve all the issues and confusion but it would make a lot more sense for that portion of the process.