Calculating post-boil OG

[Pilamman]

What's the formula for calculating either OG when hitting final post-boil volume or target volume to achieve an OG? For example, pre-boil gravity =1.052, at 6.5 gallon. Target = 1.060, what's final volume? Or, what will OG be when I boil down to 5 gallon?

Thanks!

 

[CBMbrewer]

Google is your friend.
http://www.google.com/#q=pre+and+post+boil+gravity+calculator

 

[zachattack]

What's the formula for calculating either OG when hitting final post-boil volume or target volume to achieve an OG? For example, pre-boil gravity =1.052, at 6.5 gallon. Target = 1.060, what's final volume? Or, what will OG be when I boil down to 5 gallon?

Thanks!

The total gravity points (gravity points * volume) stay the same, so it helps to think about it that way.

52 points x 6.5 gallons = 338 points*gallons (or total points)

338 total points / 60 points = 5.63 gallons

338 total points / 5 gallons = 67.6 points so 1.068 OG

 

[Pilamman]

Many thanks! Embarrassed I hadn't figured it out me ownself