Red Ale Alcohol Content

I just figured the alcohol content of the first Beer.  The Red Ale has an alcohol content by weight of 3.3%.  It has a by volume content (which is standard in home brews and non U.S. means of measuring) of 4.13%.  Respectable for our first, but hopefully the next will be higher.

The alcohol content was determined by subtracting the Original Gravity (OG) from the Specific Gravity (SG).  This amount was then multiplied by 105 for the Alcohol by Weight (abw).  For example with this beer:

(OG-SG) x 105 = a.b.w. , or (1.0475-1.016) x 105 = 3.3075, or 3.3%.

To determine by content by volume we multiply % a.b.w. by 1.25 for the amount:

3.3 x 1.25 = 4.13% b.v. 

Another way is to take the difference of the OG and SG, multiply by 1.05, then take that number and divide by the SG, but that's a lot more work for relatively equal results. 

For a standard comparison here are some alcohol contents, by volume, of some popular brews:

Anchor Liberty Ale - 6.0
Blue Moon - 5.4
Bud Light - 4.2
Corona Light - 4.5
Heineken Light - 3.5

So the beer is on the low end of the alcohol content spectrum, but it's a starting point for comparison.