Trying to make sense of the checkbox on the complete recipe builder, and how it relates to the equipment profile, and the OG calculator and brewhouse efficiency. Comparing it to my other software I think I've figured it out, and just want to double check if this is the intended usage. Test recipe: https://beta.brewersfriend.com/homebrew/recipe/view/845156/testing Equipment profile: Batch Size 42 Gallons Boil Rate 67 Qt/Hr Absorption 0.32 qt/lb Kettle deadspace 16 qt Working backwards through the volumes Postboil should be ( 42 gallons + 4 gallon deadspace ) = 46 gallons, or 47.84 gallons at boil temp. Preboil should be one of the following depending on which volumes are treated with the 4% volumetric expansion coefficient. 62.75 = (46 + 67/4). This is what's listed in the "quick water requirements section" btw, which suggests that water volumes are not treated with the 4% expansion coefficient. 63.42 = 46 + (67/4) * 1.04. This would be if the boil off rate was treated as a HOT measurement. 64.59 = 47.84 + (67/4) , this would be if the kettle losses was a HOT measurement, but boil off was not. This would also apply for any "no chill brewers" that have kettle losses. or lastly 65.26 = 47.84 + (67/4) * 1.04. For kettle losses and boil off being treated as HOT. However the only way to get the "correct" OG of 1.071 is to enter a boil size of 58.5-59 gallons, which lines up with the batch size + boil off, and does not include the kettle deadspace which it should. My best guess is that the "Use Boil Size and Boil Evaporation Rate:" checkbox is not accounting for the kettle losses in some way? Also, when the checkbox is selected, the sigfigs on the OG at the bottom of the fermentables section changes to include 2 decimal points.