How to Test Ketone Levels

When you first begin to eat a ketogenic diet, you want to know for sure that you are reaching ketosis. That’s understandable. Fortunately, for those who aren’t comfortable relying on keto “symptoms,” there are some easy ways to test for ketosis, using urine, breath and blood tests. 


This is the cheapest and easiest method to use, and it checks for the ketone acetoacetate. You urinate on a single-use strip (or dip it into a sample in a collection cup), wait the required time and compare the color change to the chart on the bottle. Darker purple usually means more ketones detected, though the test doesn’t need to show the darkest color for you to be in effective ketosis. The strips usually have a 90 day shelf life once you open them. 

These strips are widely available, 100 to a bottle and usually around 10 cents each. That is a very small investment! The one downside to this method of testing is that it relies on excess ketones spilling into your urine. Less spillage happens as your body adjusts to using ketones. That can eventually lead to a negative result even when you are in ketosis. 

On the positive side, urine testing is a cheap way to get quick feedback when starting out on the keto diet. It can take up to a few months to become keto adapted and for the strips to become ineffective. In the meantime, they are an ideal tool while you are figuring out your optimal carb range. They’ll let you know if you slip up, and the strips will also work again if you stray from keto and then return to it.


This method of testing detects the ketone acetone (which results from the breakdown of acetoacetate). It is pretty reliable, but it can be thrown off by drinking alcohol and how hydrated you are. There aren’t many ketone-specific breath analyzers on the market, and they aren’t cheap either. The leading brand’s breath monitor is about $300. That’s a lot to shell out up front. 

Some people have successfully used inexpensive alcohol breath analyzers for testing breath ketones. The downside is that there is usually math involved to convert the results to the right measurement. (As a side note, being in ketosis can also affect what you blow at a DUI traffic stop. Since you’ll also be much more susceptible to alcohol’s effects, play it safe. Don’t drink and drive.) 

The pros to breath testing are the one-time cost for the meter and that you don’t need blood or urine to test. At the same time, the cost is also a negative.


Checking blood ketone levels is the most consistent and accurate way to test. It requires a reusable meter, single-use strips and a lancet (not to be shared with other users). Since it detects the current level of beta-hydroxybutyrate (BHB) circulating in your blood, it is always going to be quite accurate. 

The necessary items usually come as a kit and require you to purchase additional strips as needed. Extra lancets and alcohol swabs are also available. The kits (which include 10 strips) are between $50 to $80. The strips for these used to be much more expensive, but they’ve come down to around $1.25 each and are usually sold in a 10-pack. 

The downsides to blood testing are the higher cost for strips, the replacement of lancets and the need to draw a drop of blood each time you test.

Keto Diet Cheat Sheet


This is a personal question and can be based on several factors. Consider whether you are put off by bodily fluids or the pain of a jab. Think about how often and how long you want to continue testing. Your budget will also come into play. 

While all these things can affect your answer, we think urine test strips are a great place to start. They will fit in everyone’s budget and help you while you get a feel for ketosis and the right things to eat. If you get comfortable with what to eat, you may not feel the need to continue testing. In that case, you haven’t spent a lot of money on something you won’t use anymore. 

You can always make a larger investment later – if you decide you would like to keep testing long-term. For now though, we recommend urine ketone test strips for their ease of use and small price tag. 

Below is a Keto Test Article that reviewed a wide range of test strips.

Quick Strip Usage Guide


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