"...the .4 was hit or miss -i rarely use full water..." Yep, same here. I am wary of swallowing "common wisdom" without first chewing it well. When I read about the 0.4 rule, I took the time to figure it out for myself. I realized it would overestimate the size of my molds, so I just did the math from scratch to figure the mold sizes I wanted. On a slab mold, oversizing the depth of the mold is not a big deal. But for a loaf mold, the bar size and shape can get really messed up if the volume calculation is not reasonably accurate.