Hydrometer question

[Seven7]

HI,
I would like to know what is your best/accurate technique to calculate the ABV of your beer.
I'm asking it because I broke my hydrometer, just bought a new one and came with instructions. For the last year I was using a little app for my phone to calculate the%
But when I tried the instructions, my beer went from 5.6% to 6.6%
So I'm curious to know which one is good?
I also include the instruction that came with the hydrometer
OG: 1.048
FG: 1.006

Cheers,

Oh I forgot to mention this ... the formula that came with the hydrometer (example):
Initial SP.GR: 1.040 = 4.7
Final SP.GR: 1.010 = 0.1
Alcohol content = 4.6%

 

[flars]

I am not sure, but the chart looks like it may using OG of a must to estimate the potential ABV of wine.
ABV for beer is calculated by comparing OG and FG. Using the Brewers Friend calculator you ABV is 5.51%.

http://www.brewersfriend.com/abv-calculator/

 

[snowveil]

(Starting Gravity Points - Finishing Gravity Points) * .131

IE, 1.048 - 1.010 (or, 48 - 10) = 38.

Multiply that by .131 and you get 4.97% ...roughly 5%

 

[unionrdr]

I've many different formulas for calculating ABV% & they all give different answers. I use Cooper's formula of; (OG-FG)/7.46 + .5= ABV%. So your numbers give 6.13%. I also noticed the Cooper's formula gives an answer in range of what BS2 gives as well.