5 Best Ketone Breath Meters in 2023 [+Beginner’s Guide]

best ketone breath analyzer big

In a hurry? The best ketone breath meter is Keyto breathalyzer!

Does your breath smell bad? Are you in ketosis yet?

Are you sure?

The truth is, without using a ketone measuring device, you can’t be.

You would want to know:

  • if you are already burning fat,
  • if your body produces Acetone, and
  • if you want to know how your body reacts to foods.
best ketone breath analyzer

Whatever the case, measuring your ketone levels is essential when it comes to fat burning and ketosis.

Breath analyzer is the most convenient way to measure breath ketones during the ketogenic diet and is actually the cheapest in the long run.

Keto breath meters we cover in this article:

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How does ketone breath analyzer work?

According to keto studies, while on a ketogenic diet, the restriction of carbs leads to the body utilizing fats for fuel.

Acetoacetate can then be converted to the other two ketone bodies, acetone and BHB (b-hydroxybutyrate).

ketonix breath analyzer

Breath ketones (Acetone) is spontaneously released when fat is metabolised into ketone energy. 

  • B-hydroxybutyrate is measured by using blood meters, while acetone diffuses in the lungs and can, therefore, be measured by testing exhaled breath.
  • A ketone breath meter is a device which measures the amount of acetone in your breath.

Unlike other methods such as urine strips or blood tests, breath ketones levels does not depend on fluid logistics, minerals or vitamins etc.

The more breath ketones, the more fat is metabolised into energy. Breath samples are non invasive and can be done many times throughout the day without extra costs. 

This makes your ketogenic diet journey way more enjoyable.

Ketone breath analyzer works like this:

  • You breathe into a tube that measures certain elements on your breath. In this case, acetone—which is also responsible for making your breath stinky in ketosis. 
  • The higher your score, the deeper you are in ketosis and the more successful you may be on the keto diet.

Research has shown that breath acetone is a reliable indicator of ketosis in people who consume low-carb meals. (1) Whether it’s your first time trying out low carb diet or you are deeply into ketogenic diet, a ketone breath meter can be a handy tool.

Breath analyzer vs. bloodketone meter

Even though blood ketone meters are considered to be the gold standard, there are multiple advantages to using a ketone breath meter instead.

breathalyzer vs blood ketone meter keto

Ease of use

  • Ketone breath meter is the easiest and most convenient to use. Perfect when you cannot pee on a stick or you are on the go. Simply blow some air into the device, and you get accurate results within seconds. 
  • Probably the biggest downside with blood meter is that for every measurement you need to prick your finger. If you don’t like blood then it can be a dealbreaker. Also this process requires quite clean environment.
  • Most breath meters (with a couple of exceptions) are the size of a pen (bulky), so it fits perfectly into your pocket and you can test your breath ketones in a Uber or a Yoga class.


  • With any meter, you must take the total price into account – the price of the meter itself plus any additional fees for continual use.
  • If you go for a blood ketone meter, you’d usually spend about 50-100$ on the starting kit, and then about a dollar per strip for each additional testing. And if you want to test your ketones 2 or 3 times a day, you can see how the total cost can pile up quickly.
  • Now, with breath ketone meters, there is no additional cost. Most of them are usually a bit more expensive than blood ketone meters (about 100-200$, depending on the brand), but you just buy them once and use them basically forever.


  • Blood ketone meters are the most accurate (and most expensive) way to measure ketones. They measure the exact amount of the BHB’s in the blood – an exact number reading (mmol/L). 
  • Breath analyzers provide the second most precise ketone readings. Measure the amount of acetone in the breath – range in PPM (parts per million). According to research, measuring breath acetone levels provides a non-invasive tool for monitoring the rate of fat loss in healthy subjects. (2)
  • Urine strips are the third and least effective way to measure ketones. These test strips measure the excess concentration of Acetoacetate in the urine. The issue here is that over time the body adapts to excrete fewer ketones in the urine. Ketone test strips can be useful if it’s your first time doing low carb and you want to see how your body reacts.

Can you just use a cheap breathalyzer instead?

In theory, yes, you can. When it comes to alcohol breathalyzers, they have two types of sensors.

  • Cheap breathalyzers have a “semiconductor” sensor, and the more expensive ones use a “fuel conductor” sensor. 
  • And unlike the latter, the semiconductor sensors can’t tell the difference between Acetone and Ethanol (alcohol), which is actually good if you want to test your breath for Acetone.
cheap breathalyzers

Now, considering the price/quality of the device, accuracy-wise, they won’t be even close to the more expensive types of breathalyzers made specifically for Acetone testing.

Cheap breathalyzers can give you a general idea of how much Acetone you have in your breath, but because of the quality, your results will vary a lot.

If it’s your first time doing low carb then you can play around with it. If you are serious about getting quality feedback, we strongly suggest you opt for some of the other options we discuss at the end of the article.

Will I also get in trouble with the police then?

And if you were just wondering, no, you won’t get in trouble if the police ask you to do a breathalyzer test.

Nowadays they all use the more expensive types of breathalyzers that use a fuel conductor sensor.

Tips for measuring breath ketone levels

When and how often should you test your breath ketones?

The advantage of breath meters is that you can use them for an infinite amount of times, so you can afford to test multiple times a day.

But, when testing, you still need to do it with a purpose in mind. You are still on ketogenic diet and your goal is to stay in ketosis.

  • Choose a time that’s convenient for you and make a routine to test daily, you will be able to compare your results to prior days at the same time and get some good data out of it.
  • If you decide to test in the morning, note that due to the “dawn effect”, ketone levels are lower and blood glucose levels are higher as compared to later in the day. (3) If you, however, choose to test later in the day, the best time would be before you have a meal.
  • Another trick is to see how you are reacting to the foods you are eating. Test once before you have the meal, and then 30, 60, and 120 minutes after eating. This shows what effect the food you eat has on your ketone levels. Also, you can do this same test for your blood glucose levels as well.
ketone breath level readings

Breath acetone ketosis levels

  • Breath acetone can range in concentration from 1 ppm in healthy non-dieting people to 1.250 ppm in diabetic ketoacidosis. In healthy individuals, breath acetone levels can be affected by multiple factors, like dietary macronutrient composition, caloric restriction, exercise, and some other more minor factors.
  • When testing your acetone levels with a breath meter, you will get back a number in PPM (parts per million). The breath value ranges for nutritional ketosis are 4-30 PPM, so you’d want your number to fall somewhere within this range. If you are at 0, you are not in ketosis at all, if you are at 1, 2, or 3, you are in a light state of ketosis, but you would want to try and increase it, so it fits the range.
  • Most of the breath meters nowadays use the PPM metric system, but if yours happens to be in nM (molar basis), the conversion is 1 ppm = 39.7 nM.

Best ketone breath meters

#1. Ketonix

The Ketonix is the oldest breath analyzer on the market. It’s made by a Swedish health care company. 

The device is the size of a marker pen, so it’s very convenient to carry around and test on-the-go.

It can be used either wirelessly by using the battery that comes with it, or by connecting the device through a USB cable (the USB cable is provided as well).

Ketonix comes with software that you can use either on your desktop pc or mobile phone (depends on the model), which allows you to input and log your readings and analyze your current state of ketosis.


The device of this review is their latest one, there are other 3 older versions of it that are a bit cheaper but have fewer features. 

» Check out Ketonix breathalyzer here

The good

  • Approved for accuracy by the FDA
  • Small in size and lightweight
  • Comes with software which allows you to log and analyze your data
  • Can connect to your pc or phone via Bluetooth

The bad

  • Can be difficult to find if you live outside US/UK
  • Takes a long time to charge the battery
  • The app screen gets glitchy at times and doesn’t show a reading

To use it, you simply blow into the device for a few seconds, after which a LED light on it will change its color based on the current level of Acetone in your breath.

Green light = small trace of breath ketones, Yellow = moderate trace of breath ketones, and Red = high trace of breath ketones. 

This range can also be adjusted to your liking so that you get the most meaningful feedback.

» Check the price of Ketonix here

Price: 239$Memory: UnlimitedPackage includes: breath ketone device, Bluetooth attachment, USB cable, battery, cable for recharging the battery, 1 extra mouthpiece, carrying case

#2. Keyto

The Keyto breath analyzer is another device specifically made for people following the keto diet. 

The Keyto breath analyzer is the size of a bulky pen, it has a circular shape, and it only weighs 27 grams (0.95 oz), so it’s portable and convenient to carry with you at all times.

It’s a lot cheaper than some of the other more popular breath meters and that’s why it’s the best ketone breath meter right now.

The company claims it’s as accurate as the other top-quality meters and it provides fast and precise results. But, it’s not FDA approved, and therefore we can’t really know for sure how accurate it actually is.

keyto breath analyzer

» Check the price of Keyto here

The good

  • Small size and very lightweight, convenient to use and carry around   
  • The Keyto app gives you tips and personalised meal plans based on your breath results
  • Very competitive price  
  • Their website has a bunch of free info on the Keto diet, including food lists, blogs, and articles, product reviews, etc.

The bad

  • Not FDA approved for accuracy
  • The device can be bought only on the Keyto official website

To use it, you first need to connect the device to your smartphone Keyto app, after which you input your body measurements, age, and goals.

Afterwards, you simply breathe into the device, and after a 10 second processing period, you get your breath reading on the app screen.

It tells you your score, in what level of ketosis you currently are (none, light, medium, deep), and based on your score.

It also gives you tips on how you can improve your state of ketosis by providing personalised meal plans, keto-recipes, and other useful ideas on low carb lifestyle.

» Check the price of Keyto here

Meter price: 99$ (sensor only)Memory: UnlimitedPackage includes: Keyto breath analyzer, 4 mouthpieces, AAA battery, carrying case

#3. House of Keto Monitor

House of Keto Monitor is another cheaper alternative to premium keto breathalyzers.

It has a small and light formfactor, making it easy to take with you (although it doesn’t come with a case).

The company states that it takes 10 seconds to measure your ketone levels.

House of Keto Meter is simple to use – just hit the button and once the countdown ends blow into the mouthpiece.

» Check out House of Keto Monitor here

house of keto breath analyzer

The good

  • Small in size and lightweight, convenient to carry around
  • The official website has a blog with free useful Keto material
  • Cheap compared to competitors
  • 30-day money back guarantee
  • Has a on-device screen for readings

The bad

  • Doesn’t come with a case (not travel friendly)
  • Most accurate only when you are in higher state of ketosis
  • Not FDA approved

Overall the device is decent enough and if you are on a budget then it may be worth trying it out. But if you are serious about ketogenic diet and weight loss then we suggest #2. Keyto breathalyzer.

» Check out House of Keto Monitor here

Meter price: 29.95$Memory: UnlimitedPackage includes: House of Keto Meter, 4 mouthpieces, 1 manual, power input (batteries are not included), 1-year warranty

#4. LEVLhome

LEVLhome is a top of the line breath ketone analyzer made by Medamonitor. 

The device is the size of a small box, and it has a rounded shape – it’s meant to sit on top of a desk or a table.

LEVL comes with an optional app which allows you to save your readings of ketone levels, analyze data, show trends over time, let you know how much fat you are burning at specific Acetone levels and more. 

If you don’t use the app, your reading will be displayed on a LED light on the device just like the Ketonix, but if you do, you will get a much more precise reading (in decimals) on your app screen.

» Check out LEVLhome here

levlhome keto breath analyzer

The good

  • Highly accurate and fast results
  • FDA approved
  • Up to 2 people can use the device
  • Great App interface and features

The bad

  • Quite pricy for personal use
  • Takes a long time to set up the device
  • Not very portable because of its size

The LEVLhome device uses a subscription payment plan of 99$/month, for a minimum of 3 months time. You basically “lease” the device for a minimum of 3 months, and then return it whenever you want to stop your subscription plan.

With the subscription, you get the right to still keep and use the analyzer and receive monthly sensor refills and calibration gas to ensure optimal device accuracy. Great option if you are serious about ketogenic diet and keep an eye on your ketone levels daily.

» Check out LEVLhome here

Meter price: 99$/month subscriptionMemory: UnlimitedPackage includes: breath ketone analyzer device, 1 power cord, 2 breath pods, 25 disposable mouthpieces, 1 set of calibration canisters (6-month supply)

#5. KHC M3

The KHC M3 Ketone breath meter is about the size of a protein bar, and it’s very lightweight, so it’s portable and convenient to carry around.

Sadly, it doesn’t have smartphone App integration like most of the other devices. 

The company claims that the devices uses a “mini-solenoid internal breath pump” which ensures the most accurate and efficient ketone readings.

We can’t say for sure how precise the readings are since the device is not yet tested and approved by the FDA. 

khc m3 keto breath meter

The good

  • Very cheap
  • Small in size and lightweight, convenient to carry around
  • The official website has a blog with free useful Keto material
  • Worldwide shipping

The bad

  • Not FDA approved for accuracy
  • Doesn’t have smartphone App functionality
  • Can buy it only from the KHC official website
  • Feels cheap

It’s pretty easy and straightforward to use. You simply power it on by pushing the button, then breath into the device and the results will show up on the screen after 10 seconds.

Meter price: 48.95$Memory: UnlimitedPackage includes: KHC M3 ketone breath meter, 6 mouthpieces, 1 manual, power input (batteries are not included), 1-year warranty


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