Do Home Breathalyzers Work?

personal Breathalyzer

Drunk driving is a problem in the United States and has been ever since the release of the automobile.  

Every day around 32 people in the US die in drunk-driving crashes.

Several solutions are available to help reduce the number of drunk drivers on the road. 

There are “drunk cabs”—a free service that takes intoxicated people home safely. Designated drivers are also an option, as is using Uber or Lyft. 

Then there is the personal blood alcohol content (BAC) calculators. These are growing in popularity while many simultaneously call their accuracy and impact into question. 

That leaves us to question that while the concept of a home breathalyzer is incredibly creative, is it effective?

Key Takeaways:

  • Nothing will ensure you avoid a DUI better than finding a safe alternative way to get home other than driving yourself. Lining up a designated driver ahead of time or committing to using a rideshare service or mass transit it your best option.
  • Not all home breathalyzers are created equal and none of them are 100% accurate.
  • Your lung capacity, weight, health and lifestyle along with the calibration of your home breathalyzer can heavily impact your reading. It might even indicate a safe level of alcohol in your system when in fact you aren’t sober enough to get behind the wheel.

Home Breathalyzers Are Accessible, but Are They Reliable?

Before there were personal breathalyzers, there were websites to help drinkers learn their limits. The idea is that if you know your limit before you go out, you won’t over-consume. Of course, that’s not always how it works when you’re in the moment. Relying solely on this practice didn’t effectively reduce drunk driving. 

We know alcohol-related self-control isn’t everyone’s forte. That’s why several companies released portable personal breathalyzer technology to help drivers determine whether it’s safe to get behind the wheel. 

The intent is simple and good-willed, but the reality may vary.

The Pros of Using a Personal Breathalyzer

Since they are portable, you can take these BAC testers to the restaurant, bar, or party in your back pocket or purse. 

Then, you can use it near the end of the evening to determine whether you need to call an Uber or see if you can get behind the wheel. 

The Downsides of Using a Personal Breathalyzer

The reliability of personal breathalyzers is up for debate. 

The devices are portable, so they’re relatively sturdy on the outside. However, they contain delicate, calibrated parts inside. The device may not work correctly if the device is banged up too much throughout the day or evening. Therefore, it’s not entirely reliable. 

Also, consider that using this device while intoxicated may lead to an increase in user error. We also know your judgment isn’t the best when you’ve been drinking, so even if you test over the limit, you might believe you’re sober enough to drive home and still get behind the wheel. 

In reality, the only ‘safe’ strategy to avoid driving while intoxicated is to plan your route home in advance. That means you know before going out who your designated driver is or whether you will take a taxi or mass transit home. 

Factors a Personal Breathalyzer Doesn’t Consider

man using a home breathalyzer

Most of a home breathalyzer’s function is fundamental science – they aren’t complex devices. But since they’re pure science, they don’t consider all necessary factors when determining whether it’s safe for you to drive home. 

Here are some things that can impact a breathalyzer’s reading, but aren’t considered. 

Lung Capacity

Breathalyzers measure the concentration of alcohol on your breath. If you have a higher-than-average lung capacity, one drink will register differently for you than for someone with a standard lung capacity. Essentially, the more air you have in a breath, the more diluted the alcohol.

Body Weight

Similar to lung capacity, body weight has a definite effect on your breathalyzer results. Let’s say you weigh 210 pounds and have two beers. Your BAC reading would be higher than someone who weighs 120 pounds and has two beers.

Health and Lifestyle

Some chemicals in your body can affect the reading of a breathalyzer too. For that reason, smokers and people with diabetes or liver conditions are at risk for inaccurate readings.


Professional-grade breathalyzers used by law enforcement are expensive devices. They are calibrated regularly by trained professionals and are accurate within a very narrow range. Personal breathalyzers can cost as little as $20 and rarely — if ever — enjoy such careful calibration. As a result, the results you might get from a personal breathalyzer can vary wildly. There’s a reason they often say ‘for novelty purposes only’ on the packaging. 

The Best Home Breathalyzers

Before we compare the personal breathalyzers, it’s important to remember this. Using the best breathalyzer that’s for sale doesn’t guarantee it’s safe for you to drive. Use your own breathalyzer at your own risk. 

  • The BACtrack S80 is one of the most accurate personal breathalyzers on the market. Someone once drank in a police station (for the sake of safe, controlled research) and deemed that not only was this personal breathalyzer the clear winner but that it was the only contender. Remember that ‘most accurate’ still has a margin of error of .005, which can mean the difference between getting a DUI or not.
  • If novelty is more important to you than accuracy (the BACtrack S80 ran $135), there are other options. A keychain breathalyzer called BACtrack Keychain is only $30. It comes in fun colors and is much more convenient to carry around. However, this model is much less accurate, running a margin of error of .02%.
  • Maybe you’ve made it this far and are thinking; there’s got to be an app for this. Alas, there is, and it’s BACtrack Mobile. Our third pick falls between the two previous choices and offers a unique feature. BACtrack Mobile will take your test results and estimate when you’ll be back to 0 blood alcohol level.

The Difference Between Personal Breathalyzers and Blood Alcohol Calculators matters

Consumers use personal blood alcohol calculators based on the premise that they will accurately tell the user when they are too drunk to drive. The problem is there is often a disconnect between how the blood alcohol calculator and the personal breathalyzer work. 

Blood Alcohol Calculators (such as B4UDrink) forecast your blood alcohol, given variables such as height, weight, age, and drinks consumed over a given period. 

Breathalyzers measure your blood alcohol via the amount of alcohol vapor you exhale. Unfortunately, many factors are at play, causing personal breathalyzers to often be inaccurate. 

For this reason, a personal breathalyzer might be a fun toy, but just because it says you’re good to drive doesn’t make it so. Passing a personal breathalyzer test doesn’t mean you won’t get a DUI, injure yourself or someone else behind the wheel. 

An excellent point to remember is using a home breathalyzer to see if you’re too drunk to drive often means you shouldn’t get behind the wheel. 

It’s everyone’s responsibility to take precautions and not leave it up to chance or inaccurate instruments. If you’re planning on drinking, always plan how you will get home in advance – a ride from a friend, a cab, or a designated driver. It’s the only surefire way to avoid a DUI.

What’s an Ignition Interlock Device?

man using an ignition interlock device

In many states, ignition interlock devices (IIDs) are another common tool to prevent drunk driving. Some state courts require you to use this device if you are convicted of a DUI – it’s not typically available for the general public.

An IID is a small device that prevents you from starting your vehicle if you have alcohol in your system. The portable device tests a driver’s breath alcohol content to ensure it’s within the legal limit. If you fail the test, you can’t start your car. 

If you do pass, you may have to retest regularly to confirm you’re remaining sober while behind the wheel. 

Typically, an IID isn’t for personal use, and you won’t need to get an IID unless the state orders it. 

Although this handy unit can get you back on the road after a DUI, the cost is between $60 to $90 per month. 

Home Breathalyzer: Frequently Asked Questions

Is buying a breathalyzer worth it?

A home breathalyzer is a relatively affordable way for you to test your alcohol content. With your breathalyzer, you can get an idea of how much alcohol you consume. 

Although you might not receive accurate results every time, the information can be helpful. But your test results won’t be as accurate as those of a professional breathalyzer. 

Can you buy an over-the-counter breathalyzer?

Yes, you can buy some models of home breathalyzers over the counter. Before committing to a particular device, read the reviews to find a quality product that offers fairly accurate readings at a price point you can afford. 

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