Finding FG with OG and ABV - I no math

[TravelingLight]

Math is not my strong suit. I searched for this but couldn't find it. I want to know how to figure out FG when I know the OG and the ABV.

We all know to find ABV: (OG - FG) x 131 = ABV

But let's say I have a beer that I know is 1.064 OG and 7.8% ABV. How would I figure out the FG based on those numbers? So...

(1.064 - FG) x 131 = 7.8 <---Solve for FG

 

[jjw5015]

1.004

 

[Gavin C]

Math is not my strong suit. I searched for this but couldn't find it. I want to know how to figure out FG when I know the OG and the ABV.

We all know to find ABV: (OG - FG) x 131 = ABV

But let's say I have a beer that I know is 1.064 OG and 7.8% ABV. How would I figure out the FG based on those numbers? So...

(1.064 - FG) x 131 = 7.8 <---Solve for FG

(a-x)131=7.8

a-x=7.8/131

-x= 7.8/131 -a

x=a-7.8/131 [a=1.064]

= 1.064-0.0595

= 1.0045

OG ~1.005

 

[bferullo]

Roughly....and you can back check your math with this site by plugging in what you come up with and comparing it to your estimated ABV:
http://www.brewersfriend.com/abv-calculator/


(1.064-FG) x 131 = 7.8

1.064-FG = 7.8/131 >> solve right side and then rearrange to get below

1.064 = .0595419 + FG >> solve for FG as below

1.064 - .0595419 = FG

FG = 1.004

 

[normonster]

https://mathway.com/

 

[FloppyKnockers]

X = me drinking the beer.

 

[TravelingLight]

Thanks dudes. Much appreciated.