Ketone bodies explained: How to measure ketone levels?

Measuring ketone bodies

Ketosis is an awesome superpower of our bodies. This can be used for rapid fat loss, curing diseases, improving physical and mental performance.

It is a metabolic state, where your body starts using fat as fuel, resulting in fat loss.

But the real question remains, how in the world are you supposed to know, if you are in a state of ketosis or not?

Well, we need to measure ketone bodies right?

Without an accurate measurement method, it is very hard to achieve an optimized ketogenic diet, which you can take advantage of.

Well, fear not, that’s what this article is all about. We are going to cover everything from what to measure up to tips and tricks on how to get the most accurate results possible.

Let’s take the guessing out of the equation.

Before we dive deep into measuring ketone bodies, first let’s go over some basics of what we actually are measuring.

What are ketone bodies?

The short answer is ketone bodies. Ketone bodies are produced by the liver from fatty acids. Your body starts producing ketone bodies thanks to low carb restrictive diets and fasting.

Your body produces three types of ketone bodies when in ketosis: Acetoacetate (AcAc) in the urine, beta-hydroxybutyric acid (BHB) in the blood and acetone in the breath.

Two first ones are used as a vital source of energy in the heart and brain, during fasting. The last one is a waste product excreted from the body.[1] 

Three types of ketone bodies

The best part of measuring ketones is that you can measure all 3 types from the very comfort of your home, by yourself.

How to measure ketones?

There are 3 different methods for measuring ketosis levels in your body: with urine ketone test strips, with blood ketone meter, and with breathalyzer.

Method 1: Testing urine with ketone strips

measure ketone levels

For decades, the traditional method for measuring the amount of ketone bodies has been testing the acetoacetate levels in the urine, using ketone test strips.

The deeper you will get into ketosis, your body will adapt and become more optimized in ketone production.

The ketone test strips will change the color, depending on the amount of ketone bodies in the urine. If you are just starting out you may see beige (no colors), pink (some ketones) or purple (a lot of ketones).

The biggest downfall with these is that after a transition period from sugar-burner to fat-burner aka when you are keto-adapted, ketones often stop spilling over in the urine, giving a false impression you being out of ketosis.

But in reality, your ketones are just not showing up in the blood and you are experiencing the long awaited benefits of nutritional ketosis.

Ketone test strips are the perfect method for everyone who are just starting out.

Once you are keto-adapted then you should consider alternative measuring methods like breath monitor and blood testing.

Good to know

  • To double your money’s worth, cut the urine strips in half lengthwise and use half of the strip during measurement.
  • Keep in mind, that the at-home urinary dipstick tends to overestimate the amount of acetoacetate in urine, but still gives you a good answer if you are in ketosis or not.


  • The cheapest method for testing ketone levels
  • Completely painless
  • Simple to use and understandable
  • If you have ketones in the urine then you are definitely in ketosis


  • Only measures ketone bodies in the urine
  • Cannot be used for long term ketosis measurement
  • You can be in ketosis without seeing ketone bodies in the urine (keto adapted)
  • High water Intake may dilute the concentration of ketones in your urine, resulting inaccurate results

For whom is it for

It’s perfect for beginners who are just starting out. Also, as they are very affordable they are perfect for everyone who needs to verify cheaply if they are in ketosis or not.

>>Check here if you want fast and cheap way to measure ketosis

Method 2: Testing breath with ketone meter

ketone breath meter

Probably the most tangible type of ketone body is acetone as you can measure it with breath ketone meter as well as you can feel it from your own breath.

This is sometimes called keto breath or dragon breath – thanks to strong aroma.

The ketone body in your breath is called acetone (keto breath). Yes, the very same molecule which is used in many nail polishes and is recognizable with the strong smell.

In the simplest terms, breath testing will tell you if you are in mild ketosis, but cannot say how deeply in ketosis you are.[4]

Acetone levels correlate well with body fat loss, that is why it is a reliable indicator of ketosis in adults consuming ketogenic meals.[5]

Breath ketone monitors have proven to be as accurate as blood ketone monitors. And since they don’t require strips they are a whole lot more affordable – and additionally, you don’t need to suffer the pain of a finger prick (like with blood meters).

They can be a pretty expensive upfront cost, but they are worth it as they are much cheaper than the regular purchases of blood ketone strips.

When you blow into the mouth piece of the breath ketone meter, the device shows a unique color, based on the level of ketones you have produced.

It’s the size of a large marker and it has the USB cord at the base.

Good to know

  • Acetone levels in breath usually lower after a high-fat meal, so always measure during the same time every day your ketosis levels.


  • Easiest test method which can be undetected anywhere
  • Only way to measure ketones (acetone) in the breath
  • Quick and painless (no finger prick)


  • May not be suitable for everyone to blow into a device for required time
  • Not commercially available world wide like other ketone tests

For whom is it for

Perfect for people, who need confirmation that they are in ketosis, without needing to know with precision in how deep in ketosis they are.

>>Check out ketone breath meter here

Method 3: Testing blood with blood ketone monitor

Precision xtra blood ketone meter

The last and the most accurate way to measure ketones in your body is with blood ketone meter.

Testing with blood ketone meter is considered to be the gold standard for testing ketone bodies, as they show a real time measurement of ketones in your blood.

The ketone blood monitor will give incredibly accurate results.

If you haven’t been used to pricking your finger for testing your blood, this can be a little bit scary at first.

Once you get over this mental roadblock you can be certain about your current situation of blood ketone levels.

Keep in mind that the blood ketone monitors are usually pretty affordable (around $30-60), but the strips can cost as much as $5 each, which can make the testing expensive.

For measuring ketones at home, you will need a blood ketone meter and a kit that includes the lancet pen and some ketone strips.

Probably the most popular one is Precision Xtra, which cans tore up to 450 measurements and will display your blood glucose averages over different time periods.

PS! Usually, you need to buy test strips separately.

Oh, and the test strips require 1.5 microliters of blood per measurement.

Good to know

  • Keep in mind to buy ketone test strips, NOT glucose test strips (as they don’t test for ketones).
  • Take blood from your fingertip, not from alternate site
  • Be sure to get the correct test strips for the correct meter (they are not interchangeable)
  • Check expiration dates on the strips as expired strips will not give accurate results


  • Most precise measurement for detecting ketones
  • No ambiguity on results with the monitor
  • Tests the most prevalent ketones in your body (BHB)


  • Testing strips can be expensive as they can cost up to $5 per strip
  • Testing supplies may be hard to find from local stores
  • Test can be painful for some people (finger prick for a blood sample), or if you are scared of blood this may not be for you

For whom is it for

It is for you if you are already in optimal ketosis and need exact results on the ketone levels in your blood. Usually, people who are in ketosis longer periods of time.

>>Click here if you want the MOST ACCURATE way to measure ketone levels

What level of ketosis is optimal?

As you might have suspected there is no one answer for everyone, as it depends on what your goals are – e.g. losing weight, mental or physical improvement or curing an illness like cancer.

Okay, but what are the optimal ketone levels in general? The ketosis levels will vary, depending on the amount of ketones your body produces.

There are many discussions about which level of ketosis is the most optimal, and there is no one right answer. The table below will give you a general overview of ketone level ranges.

  • Light ketosis: 0.5 – 0.8 mmol/LThe very beginning of ketosis – a good start. Beneficial but not to the full degree of nutritional ketosis. Most people enter here within 2-3 days. [2] During this stage you can see improved physical performance.
  • Medium ketosis: 0.9 – 1.4 mmol/LYou are in a good place called nutritional ketosis. Should be seeing a good effect on your weight.
  • Deep ketosis: 1.5 – 3.0 mmol/LThis is the sweet spot for fat loss and is also recommended by researchers Stephen Phinney and Jeff Volek. It takes typically 2-3 weeks to get into a deep stable ketosis. [3] During this stage you can see an improved mental performance.

Everything over 3 mmol/L is not getting any better results for you. Sometimes, higher values can also indicate, that you are not getting enough food.

Values over 6 mmol/L can show the beginning of a dangerous state called ketoacidosis – usually experienced by type 1 diabetics.

Very high levels of ketone require immediate medical attention and treatment.

Additional tips for measuring ketones

  • Always measure during the same time of the day. As the ketone concentrations are lower in the morning and higher in the evening.
  • If possible try to measure ketone levels daily.
  • Do not measure your ketone levels right after high intensity and strength training as the ketone levels are lower when your glucose levels are higher.
  • You can see some fluctuations in your ketone levels during the day which is totally normal. That’s why you need to be precise when measuring your ketone levels and do it during the same time every measurement.

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