I'm having a migraine getting these numbers to make sense. The link you gave to the Brewersfriend calculator says "Brewhouse Efficiency", but isn't it calculating lauter efficiency (given the pre-boil volume/OG data)? From what I can tell, mash, lauter and brewhouse numbers are all calculated differently, and there doesn't seem to be a consensus on what the gold standard is. Well, brewhouse is easy enough, but I'm confused about the mash/lauter numbers.

Here's my example:

3.75lb Pilsner

2lb Light Munich

0.25lb Carapils

0.25lb Crystal 60L

0.25lb Victory

4.1 gallons pre-boil volume

OG 1.046 (temp corrected)

3.3 gallons post-boil volume

OG 1.052 (temp corrected)

Brewersfriend says I have 78% "Brewhouse" efficiency (I assume it's calculating lauter efficiency, may be wrong there), and Beersmith says I have 73% brewhouse efficiency based on the wort in fermenter. If I plug the post-boil numbers into Brewersfriend (as ajf said), I get 71% brewhouse efficiency. Not like it's a huge deal, the system makes great beers, but you kind of have to understand exactly what you're getting before you can make improvements on the mash side.