Your blood alcohol concentration, or BAC, is simply a measure of the amount of alcohol in your system at any given time. This can be discovered through various means, but many police departments will simply use a Breathalyzer or a portable breath test.
The legal limit for drivers in the United States, unless they are underage or commercial drivers, is a BAC of 0.08%. So, if you’re looking to avoid getting arrested for drunk driving, you likely want to know exactly how fast your BAC will drop when you stop drinking. This can give you some indication of when it’s safe to get back in the car.
It is important to consider this, because the reality is that your BAC is only going to drop by about 0.015 per hour. This is a very slow decline. That means it often takes much longer than people expect for their BAC to get back below the legal limit or all the way back to zero.
For instance, if a man weighed 180 pounds and consumed five drinks, estimates show that it would take 6 1/2 hours for his BAC to drop back to zero. If that man had 10 drinks, it would take him 11 hours.
There are different factors that influence how high BAC gets, including weight and gender, which is why they are noted above. But the average person is still going to metabolize alcohol at the same speed, and so their BAC is likely going to drop at the same rate, even if it rose faster while they were drinking.
As you can also see, these time frames are very long. If someone is out drinking and they decide to take an hour to have a glass of water or a cup of coffee, that can certainly make them more sober than they were before. But it also may not mean that they are down below the legal limit and it is safe for them to drive. They could still have hours before they reach that point, even though they think they have done enough to avoid a DUI.
If you are now facing charges for driving under the influence, it’s important to understand exactly what legal steps you can take. This can have a big impact on your future, it can be expensive and you need to know what to do moving forward.