【How-to】How long does it take to pass a breathalyzer

So when is it safe to drive again? As a rough guide, it’s around three hours if you drink one large glass of wine (250ml/three units), about two hours to break down a weak pint of pint, cider or lager (3.6% – few drinks are this weak any more), or three hours to break down higher-strength lager, pint or cider (5.2%).