For a bit now, there has been a viral smart ring making the rounds on TikTok. People talking about these smart rings sing that it has many of the features of Oura and Ultrahuman but with prices ranging from $20-$40. from a company called Colmi. The different models range in price from about $20-$40.

I am currently on a “glow-up” journey and part of that entails trying to be more active. I don’t particularly LOVE the look of my Apple Watch, so I had been looking at smart rings as a way to continue to track my activity and motivate me, but with a sleeker look (in my opinion). I ended up buying the Colmi R09 smart ring because it claimed to track temperature, steps, heart rate, oxygen saturation, cycle, stress, and more. I also made a YouTube video reviewing (a bit more in depth) this ring if you’re interested!:

General Impressions of the Colmi R09

Truthfully, I LOVE the look of this ring. I think it looks lighter in color compared to the bionic gold color from Ultrahuman, which I really like. After over a month of wear, there is some scratching, but that seems to be a complaint with all the smart rings. The ring comes with a charging cord as well as a charging case. I prefer the charging case, but either way, I’ve found that the charge on the ring lasts 2-3 days!

My biggest gripe overall is sizing. The smallest size offered in the R09 is a size 8, which is still too big for me, and I had to add sizers in the ring. I wish a size 7 was offered because it would fit me perfectly! I do recommend using the sizing chart from Colmi and measuring your non-dominant index finger several times in centimeters to make sure you are getting an accurate sizing. I cannot confirm this completely, but I bought the Ultrahuman sizing kit for $1 and their size 7 is the same size as the Colmi size 8. So while I cannot 100% confirm that the Colmi ring is 1 size up from the Ultrahuman sizing, I suspect it.

Steps

I compared the step count from the ring versus my Apple Watch in several ways. I will preface this by saying, I am not certain if my Apple Watch is the ultimate authority in step count. There is a valid chance that my Apple Watch is under-reporting my steps and the ring is closer to the truth. Regardless, if you look overall at my day to day step count comparisons, the ring is almost always higher than the count given by my watch. Sometimes that is by 3000 steps, and sometimes it is by 600 (although I have found that the counts are closer to each other on the days where I log a walking workout).

I did test the steps a couple of ways:

1. By counting 100 steps around my kitchen in which case both the Apple Watch and the ring came very close and were only off by 3 or 4 steps.
2. By sitting in a chair for 45 minutes and seeing how my step count changed while being sedentary and simply typing on my phone and computer (both registered a similar amount of “steps”)
3. By counting 100 steps while pushing a stroller (the ring registered ZERO steps while the watch registered about 20 steps).

Exercise/Activity

Overall, the ease to track workout within the QRing/Colmi app is good; however, I am not certain about accuracy for calorie count. Whenever I log strength training workouts, the calorie counts are pretty close to what my Apple Watch logs, but other exercises like stair climber may have a bigger discrepancy.

Sleep

This is my favorite feature of this ring. I don’t wear my Apple Watch to sleep because the watch is normally dead by 9-10 pm and I would have to charge it completely before going to sleep and then charge it again in the morning to be able to wear it for the day. The long charge of the ring lets me be able to wear it while I sleep and get some data on that.

The only weird/interesting thing I found about the Colmi sleep tracking is that if you are awake for longer than about 10 minutes, it won’t register that as “awake time”, it will just leave it as a blank section and take that time out of your total sleep duration.

Heart Rate

From what I can tell, the heart rate function of the ring is accurate as long as you have a good fit on your finger. It is always very close, if not identical, to what my Apple Watch reads. You can set this to different intervals as well.

Oxygen Saturation

Also, I believe this to be accurate on the ring. It’s never told me any weird outlier numbers. This one was hard to compare to my Apple Watch readings because my watch wasn’t always consistently reading, but I do believe it is likely accurate!

Stress

This one is interesting. I’m truthfully not sure how it is calculated- whether it is HRV or heart rate; but mostly, it tells me that my stress level is normal. Sometimes it will read in the “moderate” range and does correspond to moments where I had notable stress. But my lack of readings in the “relaxed” range tells me I have some work to do!

Cycle/Ovulation/Menstruation

This was undoubtably the most dissapointing part of the ring. The ring says it tracks temperature and your cycle, and people on TikTok made some very misleading claims. Additionally, within the QRing app (the tracking app for the Colmi smart ring, in the “menstrual” tab, there is a section labeled “body temperature”. One would therefore conclude that perhaps it is using that temperature to help track ovulation and play into cycle predictions? Wrong.

I noticed throughout the day that the body temperature section within the menstrual tab would change (which shouldn’t happen if it was tracking BBT because that should just be done when one wakes up). And then when my cycle came a few days after getting the ring, I found that there is no way to enter your period and that there is no real predictive algorithm within the app or ring. I did reach out to Colmi and they confirmed this.

That being said, you COULD use the temperature tracking of the Colmi ring and use the temperature it takes right before you wake up for the day and enter it yourself into an app like Flo to do BBT. However, this integration is currently not there for the Colmi app and ring itself.

Temperature

Now in general, the temperature tracking of ANY smart ring is not going to be comparable to a true core temperature, because the farther you get from the core of your body, the more variability and less accuracy there will be. When I compare a core temperature (taken orally) to the ring’s body temperature reading, it was off by 0.5 degrees, which isn’t too bad! But there will likely be a bigger discrepancy if the ring is taking temperatures when you are not at room temperature.

Heart Rate Variability

From what I can tell, this seems accurate, especially considering the general heart rate function of the ring to be accruate. The data is very close to what the ring measures.

Verdict on The Colmi R09 Smart Ring

I really like the look and the sleep tracking features of this ring. For the most part, the app is good and user-friendly; however, I am still very disappointed by the lack of real menstrual tracking ability with this ring. There is a lot of potential there!

For $40, I think its a great introduction/starter ring to see if you are potentially interested in a smart ring, and then you can always upgrade to a more expensive one like Oura or ULTRAHUMAN.

If you have any questions about this ring or the app, feel free to ask in the comments and I’ll do my best to answer!

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