[DuffMan]

So, I was out last Saturday, playing some poker at a friends place, and had a few beers, and I do mean a few. Knowing this is a good time of the year for checkstops at 2 am, I wanted to try to figure out my BAC, before deciding on driving or drinking more heavily and ubering.
You'd figure this wouldn't be hard in this day and age, so I checked some websites and also dl'd a few apps.
It seems the results are pretty varied.
The calculation I put in is 200 lb guy drinking 4 x 5% beers over 4 hours.
results were .018 - .039, either way, way under the limit. I'm not even sure if that sounds right. I always figured, 1 beer/hour was OK, but that is almost non drinking OK levels.
Does anyone else know of a good reliable calculator/calculation? I'd rather go through a checkstop with confidence, as opposed to the high speed chase I did last Saturday.....jk.