measuring alc content????

Hello,
I have posted in the cider area as well. I dont know if im on the right area here but, I have just made my very first try at nettle Ale. It tasted Lovely, but is there anything I can use to measure the alcohol content? Its VERY fizzy!
I dont know if a hydrometer will work? the brew is obviously all finished now, so if I put some in, will this give me the current alc %?
Thanks,

Lucy

(og-fg)*131=abv

I'm not sure what a Nettle Ale is but one thing you can do is go download a free trial of the program Beer Smith. It helps build recipes and you can choose from a list of beer styles and once you enter all the ingredients and such it will give you an estimate on your OG. May not be entirely accurate, but probably close enough for you to make a judgment from a hydrometer reading.

Edit: This is assuming you don't have the OG reading.

A hydrometer just measures the gravity (density) of a liquid. Beer becomes less dense as it ferments, so the difference between the OG (original) and FG (final gravity) reflects the amount of alcohol.