# What's my ABV?

### Help Support Homebrew Talk:

##### Well-Known Member
OG of 1.094
FG of 1.028

how do I figure this?

#### EvilGnome6

##### Well-Known Member
Here's a nice calculator at BrewHeads.com. According to that, you're looking at 9.55% ABV.

og - Fg x 131

#### Travel_mon

##### Active Member

You ABV = 9.5% and 300 calories per 12oz. With an apparent attenuation of 68.5%. There is a great website that can calculate all this and a few other brewing related stuff on BrewCalcs.com.

If you want the specific formula check out John Palmer's How to Brew guide or I'm sure any google search would yield enough info.

Cheers!
Travel Mon

#### EvilGnome6

##### Well-Known Member
og - Fg x 131
That yields 8.65% with his numbers. Why the discrepancy with the other calculators?

#### Hugh_Jass

##### Well-Known Member
Is there a correction? I'm getting 8.65%

1.094-1.028=.066

.066*1.31=.08646 or 8.65%

What am I doing wrong?

#### tcklord

##### Well-Known Member
Beersmith gives 8.7%

#### maida7

##### Well-Known Member
og - Fg x 131
This is the formula I use. In fact I think it comes written on the hydrometer. Is there some sort of sliding scale for such a high SG?

#### RubenAlonzo

##### Active Member
That yields 8.65% with his numbers. Why the discrepancy with the other calculators?
I use the same formula and was wondering the same thing you asked.

#### mojotele

##### Well-Known Member
I use the simple OG-FG*131 formula as well. Count me in as another person confused by the difference.

#### A4J

##### Well-Known Member
i don't know why brewcalcs.com is way off, but there's a little bit of discrepancy to be expected between various software because of rounding error. The 131 multiplier that we all use is a rounded number.

#### maida7

##### Well-Known Member
that's a whole lot rounding

#### danculwell

##### Well-Known Member
My guess is that its not really linear like in revvys formula. That the formula is close enough for a certain range but the computers have more complicated algorithms to find it. However I may just be talking out of my ass.