How to Choose a Breathalyzer: A No-Nonsense Buying Guide

Choosing the right breathalyzer for yourself comes down to four things: accuracy, how you plan to use it, how easy it is to carry, and what it actually costs once you factor in upkeep. Get those four right and the rest, such as app tracking, color, extra mouthpieces, is just preference.

This guide walks through each factor one at a time, then matches them to specific BACtrack models, the C6, the C8, and the S80. Along the way, you'll see how sensor type affects your readings, why calibration isn't optional, and how to think about price as more than the number on the box.

What to consider when choosing a breathalyzer

Six factors decide whether a breathalyzer earns its spot on your keychain or ends up in a drawer.

• Accuracy and consistency: whether you can trust the same reading twice under the same conditions
• Sensor type, since the technology inside the device drives everything else on this list
• Calibration and upkeep, plus what that servicing costs over time
• Portability and convenience: size, battery life, and how naturally it fits your routine
• Price and total cost of ownership, the sticker price plus calibration, mouthpieces, and any repairs
• App and Bluetooth tracking, for a history of your readings instead of a single number

BACtrack's C6, C8, and S80 each hit those factors differently. A quick look at each one below shows which combination fits your situation best.

Which BACtrack device fits your needs

Here's the short version. All three run on fuel-cell sensors. They differ in sensor line, screen, and how you read your number.

• Want the most accessible way in? The BACtrack C6 ($69.99) runs on BACtrack's BluFire fuel-cell sensor in a keychain-sized body. 
• Want a bigger screen? The BACtrack C8 ($99.99) uses the same BluFire sensor with a larger display. It won’t fit on your keychain, but it will be a great addition to a happy hour or dinner party.
• Want one-button simplicity with no phone involved? The BACtrack S80 ($129.99) uses BACtrack's Xtend fuel-cell sensor. It’s a premier professional breathalyzer built for people who want the most dependable BAC results. It's part of BACtrack's Pro Grade line, which holds calibration longer than its non-Pro Grade models.
• Want to see your numbers over time? The C6 and C8 pair with the free BACtrack app over Bluetooth, which saves every reading. The S80 works on its own, so a C-series model is the better fit if history matters to you.

Portability and convenience

The C6 is the smallest of the three at 1.5 ounces, a portable, keychain-ready option for quick checks before you drive or hand it to a friend at a party. The C8 is close behind at 2 ounces, with a bigger screen that's easier to read across a table.

The S80 is the largest at 4.8 ounces with a hard-shell case. It ships with a hard-shell case and six mouthpieces, so passing it around a group is easy from day one. The pro-grade model can be used for back-to-back readings, with up to 1,500 uses on one set of batteries. That's why BACtrack positions the S80 for health professionals and other work settings as well as personal use. 

If you want a device that goes everywhere with you, whether that's a dinner out, a tailgate, or a friend's place, the C6 or C8 fits those types of outings. If you're hosting, sharing one device across a group, or need it at work, the S80 is built for that. 

Accuracy, sensor type, and calibration

Personal breathalyzers use several kinds of sensors. The two you'll run into most are fuel-cell and semiconductor.

A fuel-cell sensor turns the alcohol in your breath into a tiny electric current, and the device reads that current. It's the sensor type inside BACtrack's C6, C8, and S80.

A semiconductor sensor works differently. It uses a heated metal-oxide surface. Alcohol changes how that surface carries a current, but a number of other substances can change it too. Its response also isn't a straight line as alcohol levels climb [4]. That's a big part of why semiconductor devices cost less to build.

What does the research say about fuel-cell devices? A 2018 study from Griffith University in Queensland, Australia, asked whether portable fuel-cell breathalyzers hold up well enough for field research on drinking. Researchers took readings from 229 people in Brisbane's nightlife districts. They compared different portable fuel-cell units against a police-operated evidential breath analyzer. Readings agreed 93 to 97% of the time across four studies. Most of the disagreements showed up at higher readings, above 0.100% [1]. 

The same study notes that a fuel-cell sensor can't tell alcohol lingering in your mouth from alcohol in the deep-lung air it's built to read [1]. A recent sip of alcohol or mouthwash can push a reading higher than your actual level. NHTSA guidance points to a 15-minute wait for this reason [3]. Give it 15 minutes after your last drink or mouthwash, then blow.

Accuracy in practice means two things. Your reading stays consistent from one use to the next, and it holds up over months, not just out of the box. That second part is where calibration comes in. Every breathalyzer's sensor drifts with use, the same way a car's speedometer eventually needs a check [2]. BACtrack recommends calibrating its Pro Grade models, like the S80, at least every 12 months. Non-Pro Grade models may need service closer to every 6 months, and daily use can shorten either interval. 

Breathalyzer with a tracking app

If you want a breathalyzer for situations when you just need one reading before you head out, a standalone device does the job. But if you want to see how your numbers trend over a month, or over a season of dinner parties, a model with an app is worth a look.

The free BACtrack app, available for the C6 and C8, logs every reading with a timestamp and shows an estimate of when your BAC will return to 0.00%. The S80 skips the app in favor of speed: press the button, blow, get your number.

The C6 and C8 pair with the BACtrack app for pattern tracking. The S80 delivers a standalone number in seconds. Neither approach is wrong, it depends on what you're actually trying to know.

Price vs. value

To see which breathalyzer fits your budget, look at more than just the price of the device. Calibration is the biggest recurring cost. BACtrack’s Pro Grade breathalyzers, like the S80, hold calibration longer than its non-Pro Grade units. 

It’s recommended to calibrate Pro Grade models at least every 12 months. Models like C6 and C8 may need service closer to every 6 months, depending on the performance you observe and require. Daily use can mean calibrating more often. You can choose standard or expedited service.

*Includes the device, one 10-pack of mouthpieces, and standard calibration: two visits for the C6 and C8, one for the S80. Your total will be higher if you calibrate more often or choose expedited service.

Choose your Breathalyzer

Choosing a breathalyzer comes down to three questions: where you'll carry it, who'll use it, and how much upkeep you want to take on. And the choice doesn't end at checkout.

Every breathalyzer needs periodic calibration to keep its readings accurate, so the real cost shows up over the first year and beyond. A device that fits your routine and your upkeep budget is one you'll actually keep reaching for, long after the novelty wears off.

The BACtrack C6, C8, and S80 give you a fuel-cell reading in three different forms. The C6 rides on your keys and the C8 slips into a pocket, and both pair with the free BACtrack app. The S80 works on its own and is built to be shared across a group.

Choose your ideal breathalyzer at bactrack.com/collections/all-breathalyzers. 

FAQ

Is a cheap breathalyzer good enough?

Sensor type tells you more than price. The C6, the lowest-priced model in this guide, uses a fuel-cell sensor, like the C8 and S80. Semiconductor sensors cost less to build, but they can respond to substances other than alcohol, and their readings don't rise in a straight line as alcohol levels climb [4]. Before you buy any breathalyzer, check which sensor it uses. 

How often do the C6, C8, and S80 need calibration, and what does it cost?

BACtrack recommends calibrating Pro Grade models like the S80 at least every 12 months. It says non-Pro Grade units may need service closer to every 6 months, depending on the performance you observe and require, and daily use can mean calibrating more often. Standard calibration costs $19.99 for the C6 and $24.99 for the C8 or S80. Expedited service is $49.99 for the C6 and $54.99 for the C8 or S80. If your readings start to seem inconsistent, check in sooner.

What's actually different between a lower-priced and a higher-priced breathalyzer?

Mostly size, how you see your number, and upkeep. The C6 clips onto your keys and the C8 fits in a pocket, and both pair with the free BACtrack app. The S80 works standalone, is built to be shared, and belongs to BACtrack's Pro Grade line, which can hold calibration longer. 

Can a group or household share one device?

Yes, as long as each person uses a fresh mouthpiece and you follow the cleaning and replacement guidance in your device's manual. BACtrack sells mouthpieces in 10-packs for $7.99. If your group reaches for one device often, the S80 is built for shared use, and its Pro Grade calibration interval means fewer trips for service. 

Do I need an app, or is a standalone device enough?

It depends on what you want to know. A standalone device like the S80 gives you a number for that moment. If you want to look back at your readings over time, the C6 and C8 pair with the free BACtrack app. Either way, a reading is a personal estimate for that moment, not a legal or medical determination. 

Can anything besides alcohol affect a reading?

Yes. Alcohol left in your mouth is the most common cause of an inflated reading. It can come from a recent drink or from products that contain alcohol, like some mouthwashes. Fuel-cell sensors can't tell mouth alcohol apart from the deep-lung air they're built to read [1]. Wait at least 15 minutes after drinking or using an alcohol-containing product before you blow [3].

References

1. Sorbello et al. "Fuel-cell breathalyser use for field research: independent psychometric evaluation of portable devices" (2018) PMC5857179 https://pmc.ncbi.nlm.nih.gov/articles/PMC5857179/
2. BACtrack "Breathalyzer Calibration" https://www.bactrack.com/products/breathalyzer-calibration
3. NHTSA "DWI Detection and Standardized Field Sobriety Testing: Training Goals and Objectives” https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/2009-sfst-participant-manual.pdf 
4. US Patent 10,877,023, "Dual sensor types in breath alcohol detection." https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/10877023