I had a target OG of 1.070 and we came in at 1.060. Where does this put our efficiency? Please show/tell me how that's calculated.

Nice profile pic. There’s a calculator on this website where you plug in your grain bill, and it will calculate your efficiency or conversion for you. Brew sessions will automatically calculate it, if you plug in all of the required variables.

First, what kind of brew were you doing? Calculating efficiency for all grain is different than for extract. Efficiency is defined as the amount of extract (read sugar) you get divided by the theoretical maximum extract you could get from the grains, adjuncts, sugars, etc. That's extract efficiency. Brewer's Friend has two others, kettle and boil complete. They don't really matter so much, they're just ways of tracking sugar losses through the brewing process. You lose sugars through the process to absorption by grains and hops and by wort that doesn't make it to the fermentor (wort left under the false bottom, left in the kettle when transferring, etc.). Brewhouse efficiency measures the amount of extract that made it to the fermentor divided by the theoretical maximum mentioned above. To measure the efficiency exactly, you need to know the malt from the analysis. But you can make assumptions. And that's how the calculator works.

My sweet spot on my system is around 4kg/21 lt batch i get great efficiency round this mark. Ill be re adjusting to keg ferments soon so that is gunna need some re calibration.