Yes, me too Chippy-Tea. if you know the starting sg and final sg you can calculate the alcoholic content, otherwise you need to have a filtered sample of your finished wine and buy either a 'Vinometer' which is a glass instrument which looks a bit like a glass thistle shape on a stick and has limited accuracy for around £5 or a Refractometer which is very accurate but cost from around £20 to 'HOW MUCH!!!'
There is a third method, highly inaccurate and involves a couple of aspirin the next morning but quite enjoyable.