Circular Ring 2 tracks your heart rate 24/7 through a finger-based optical sensor, which gives better data than wrist-based monitors thanks to stronger arterial flow and less movement interference. Every reading is interpreted alongside your sleep, HRV, stress, and recovery, and an AI health coach turns the picture into one actionable recommendation a day.
Order Circular Ring 2Your heart rate is 83. And? What this number means depends on what your body was doing, how you slept, how much stress you were carrying, and what your personal normal looks like. Most wearable heart rate monitors give you only the number. Few tell you what to do with it.
Fitness trackers measure every few minutes, so the patterns that matter hide in the gaps.
Wrist monitors fight motion, sweat, and fit. The finger gives cleaner signal, right when rest and sleep matter most.
Most monitors show a number and stop. No baseline comparison, no link to your sleep or stress.
Circular Ring 2 tracks your heart rate 24/7 with an optical finger sensor. Kira AI analyzes it alongside HRV, sleep, stress, recovery, and your personal baseline to give you one clear daily recommendation.
Tracks your heart rate around the clock, so you see the full pattern, not just occasional readings.
Check your heart rate anytime in the app, before a workout, after a meeting, or whenever you need it.
Every reading is interpreted alongside your sleep, HRV, stress, recovery, and daily activity.
Exercise is automatically sorted into low, medium, and high intensity zones based on your personal heart rate.
Your heart rate is compared to your own 14 day baseline, not other people's averages.
Heart rate tracking, live readings, intensity zones, and Kira AI insights are included with your ring.
It is 2pm, and your heart rate has been higher than your normal afternoon range for over an hour. You feel okay, but the app shows the pattern clearly. Then you look back at your day: back-to-back meetings, two coffees, and no real lunch. Circular helps you see what your body was already reacting to.
You have a presentation in fifteen minutes. You open the app and check your live heart rate. The number is steadier than you expected, so you walk in calmer and more in control.
You start a workout and see which heart rate zone you are in. Moderate activity usually sits around 50–70% of your estimated maximum heart rate. Vigorous activity is closer to 70–85%. Circular helps you understand how hard your body is working, so you can train with more control.
You push hard during a session and your heart rate climbs close to your maximum range. Circular helps you see when the effort is getting too high. Staying near your maximum for too long can put extra strain on your body and make recovery harder, so you know when to ease off.
You finish a hard workout and your heart rate is high. You sit, breathe, and watch it start to drop. How quickly your heart rate settles can help you understand how your body is recovering after effort.
You have two glasses of wine with dinner. That night, your heart rate runs a little higher than usual while you sleep. You may not feel the difference in the moment, but Circular shows the pattern. After a few weeks, you can see how alcohol affects your sleep and recovery.
For three nights, your overnight heart rate is higher than usual. Circular does not predict illness, but it can help you notice when your body is under more strain than normal, so you can ease off and rest.
You train consistently for six weeks. Your average resting heart rate starts to drop, and your heart rate settles faster after workouts. Circular helps you see that your daily choices are starting to change your body.
You take a slow Sunday. A walk, less screen time, no rushed schedule. Your heart rate stays smoother through the day, and your recovery looks better the next morning. Seeing the effect helps you understand what real rest does for your body.
Kira AI reads your heart rate alongside every signal Circular Ring 2 captures, including your sleep, HRV, stress, recovery, temperature, and activity load.
The output is one clear recommendation a day. Push the session, push it back. Anchor your bedtime tonight. Take the slower morning tomorrow. The recommendation is built from your data and shaped to your day.
For continuous 24/7 tracking, Circular Ring 2 uses optical PPG (photoplethysmography), reading the blood volume pulse passing through the small arteries in your finger.
The finger is closer to strong arterial flow, has less movement interference than the wrist, and stays in firm contact with the sensor across the day and night. For a 24/7 wearable heart rate monitor, the finger often produces a cleaner signal than the wrist, especially during sleep.
Continuous background tracking through the day and night. Live on-demand readings from the app. Resting heart rate detection during sleep. Heart rate intensity zones during activity.
Heart rate trends are interpreted against your own 14-day rolling baseline. A reading that would be normal for one person can be elevated for another, which is why a personal baseline is more useful than a population chart.
Circular Ring 2 is not a medical device. It does not diagnose cardiovascular conditions, predict illness, or replace medical monitoring. For clinical concerns, share your trend data with a doctor. For irregular rhythm checks, see the on-demand ECG feature.
Loose ring fit, cold fingers, low circulation, intense movement, and dirt, lotion, or moisture on the sensor can all affect signal quality. Circular filters out low-confidence readings, but one unusual heart rate reading does not always mean something is wrong. The overall trend matters more than a single number.
Heart rate data is encrypted and processed with GDPR and HIPAA compliance.
Titanium body, hypoallergenic interior
2.55mm thick, 7.8mm wide, 3 grams
Sizes: US 6–14
Battery: 8 days (Power Mode), 5 days (Performance)
Charging: 30 mins via wireless charger
ECG, PPG, temp sensor, 3x accelerometer
Bluetooth Low Energy, Airplane Mode
iOS & Android compatible
GDPR & HIPAA compliant
"Got it for heart rate tracking and sleep mostly. Pretty happy so far. I like that it shows when my heart rate is higher than usual, especially after bad sleep or stressful days. Makes the data easier to understand."
"Didn't want to wear a watch at night so tried this ring. Much more comfortable for sleep. The heart rate and HRV stuff in the morning is useful, and the app doesn't make it too complicated."
"Good heart rate tracker. I use it for workouts but honestly noticed it more with everyday stuff. Late nights, wine, stress, all of it shows up. Battery is decent too. Would like even more detail in some reports, but overall happy."
Heart rate is the signal that connects most of what Circular tracks. Your sleep stages are partly classified by heart rate patterns. Your stress score reads heart rate alongside HRV. Your activity intensity zones are built on heart rate. Your ECG readings, your resting heart rate trends, your recovery insights, and Kira AI's daily recommendation all draw on the same continuous heart rate signal. One sensor, 14+ features, working as one.
A 40-second ECG from your finger, with irregular rhythm and AFib detection.
Learn when your body is stressed and needs rest or when it is ready to perform.
Your sleep, recovery, stress and activity combined into one daily score.
Overnight heart rate variability read against your own baseline, so you can see recovery move.
Early warnings when metrics detect something unusual before you notice.
Every movement sorted into low, medium or high effort, with a daily calorie count beyond workouts.
Circular Ring 2 measures heart rate through optical PPG, which reads blood volume changes in the small arteries of your finger. The finger gives a strong signal for heart rate tracking because it has rich blood flow and keeps close contact with the sensor.
For ECG, Circular Ring 2 uses built-in electrodes to capture the heart’s electrical signal during an on-demand reading. Together, PPG and ECG give you two different views of your heart: one for continuous heart rate tracking, and one for rhythm checks.
Yes. Circular tracks your heart rate 24/7, through the day and through the night, with resting heart rate detected during sleep and live readings available on demand.
The finger gives a cleaner optical signal than the wrist, with stronger arterial flow and less movement interference, which matters most during sleep. Loose fit, cold fingers, low circulation, intense movement and moisture on the sensor all reduce signal quality. Circular filters out low-confidence readings, and the trend over days is more reliable than any single number.
The wrist is a busy area, with tendons, bones, and thicker skin between the sensor and the signal. The finger has rich blood flow, with dense capillaries and digital arteries sitting closer to the skin’s surface. That makes the finger a better place for clean optical heart rate readings at rest and during sleep.
Wrist wearables can also slide, twist, or lose contact when you move your hand, bend your wrist, or roll over in bed. These small gaps can affect overnight readings. A chest strap is still the standard for high-intensity training, but it is not built for comfortable all-day and all-night wear. Circular Ring 2 gives you a low-profile way to track heart rate through daily life, sleep, and recovery.
Yes. Open the app and use the Live Measurement circle to check your heart rate in real time. For an on-demand ECG or heart rhythm check, use the Heart Rhythm circle.
Yes. Heart rate trends, alongside HRV, sleep, and activity load, feed into your daily Energy Score.
Yes. Resting heart rate, overnight heart rate trends, and heart rate variability all feed into your recovery picture.
Yes. Circular Ring 2 detects both high and low heart rate events and can alert you when they occur, so you have a record of when the spike or drop happened and what else was going on at the time.
No. Kira AI does not diagnose conditions, prescribe treatment, or replace medical professionals. It translates biometric signals into lifestyle and behavioral guidance you can act on. For anything clinical, the Circular app generates PDF reports and trend summaries designed to be shared with your doctor.
Yes. We encrypt data between your ring, the app, and our cloud systems. We do not sell your health data or use it for advertising, though we process and share limited data when needed to run, protect, and improve the service.
Circular Ring 2 is not intended to diagnose, treat, cure or prevent any disease, and is not for use in an emergency.
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