#### Becks the Elder

##### Country Wines.

- Joined
- Feb 23, 2009

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**Hydrometers, Refractometers, Brix, SG & abv. Conversions.**

Hi everyone,

I have been using my hydrometer and taking readings and then subtracting the finishing SG from the starting SG and dividing by 7.36 to get the abv.

I have recently been toying with the idea of buying a refractometer so started looking into the Brix scale.

I found an auto conversion webpage:

http://onebeer.net/refractometer.shtml

When I started to put some test calculations through this site I noticed it returned abv figures around 0.6% - 0.7% abv. below those that the subtraction and division method produce. I imagine the webpage results are more accurate as they calculate the figure to about 10 dec. places.

How accurate is the SG subtraction and division method at calculating abv? Would it be more accurate to calculate the abv using the subtraction and division method if the result had a final subtraction of 0.6 applied?

Maybe I've misunderstood something basic somewhere. Can anyone set me straight?

Many Thanks.

Becks.

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