Question 1

How accurate is a BAC calculator?

Accepted Answer

It's an estimate. The Widmark formula gives a reasonable approximation based on body weight, sex, and time, but actual BAC depends on food intake, hydration, medications, drink strength, and individual metabolism. Real BAC can vary by ±30% from the calculated value. Never use this to decide whether to drive — always rely on a breathalyzer or, better, don't drink and drive at all.

Question 2

What's a 'standard drink'?

Accepted Answer

In the US, one standard drink contains about 14 grams of pure alcohol — roughly one 12 oz beer (5% ABV), one 5 oz glass of wine (12% ABV), or 1.5 oz of 80-proof spirits (40% ABV). Cocktails and craft beers often contain 1.5–3 standard drinks each.

Question 3

How long does alcohol stay in your system?

Accepted Answer

The body metabolizes about 0.015% BAC per hour, regardless of body size. So a BAC of 0.08% takes roughly 5.3 hours to reach 0. Coffee, cold showers, and food do NOT speed this up — only time does.

Question 4

What's the legal driving limit?

Accepted Answer

0.08% BAC in all 50 US states (0.05% in Utah). For commercial drivers it's 0.04%, and for drivers under 21 most states have zero-tolerance laws (any detectable amount).

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