Summer sale Up to 30% off, applied at checkout Shop the sale

Features/Sleep

Want better Health? Get engaged with your sleep

Improve your sleep like never before thanks to sophisticated tracking, easy-to-read insights and a seamless smart ring.

Buy now See a night
SleepRing 78%
Last night · 23:05 → 06:38 79sleep score
7h 33m
Last night's story

A shorter night than usual, but a well-shaped one. Deep sleep landed above your baseline.

Deep sleep +12%1 disturbance
One night, minute by minute

Sleep is not one thing, so it is not scored as one.

Sleep score

79of 100

Asleep

7h 33m

Deep

1h 32m

REM

1h 50m

Awake

18m

23:19 asleep
03:12 deepest
04:40 woke briefly
06:38 smart alarm
23:0501:0003:0005:0006:38
AwakeLightDeepREM

Deep sleep clusters early, REM later. That shape matters more than the total — which is why the score reads the shape, not just the hours.

How it measures

A sleep lab in a tiny and comfy ring

Precise PPG heart rate, respiratory rate, SpO2 and motion sensors along with a machine learning powered app will help you understand and improve your sleep over the long term.

Kira never sleeps but you'll sleep better

Kira learns about your baselines to give you a daily personalized sleep quality and tells you exactly what parameters impact your sleep to improve them. Circular measures not only how long you sleep, but the time spent in each stage, your circadian rhythm, your heart rate metrics and respiratory rate.

  • Heart rateBeat to beat through the night, plus the lowest point and when it arrived.
  • HRVOvernight variability, the clearest signal of how recovery actually went.
  • Respiratory rateBreaths per minute, and any deviation from your own nightly average.
  • Blood oxygenSpO₂ sampled through the night. Patterns worth discussing with a clinician, not a diagnosis.
  • Skin temperatureDistance from your baseline — an early marker of illness and cycle phase.
  • MotionMovement and stillness, which separates awake from light sleep.
The science, in three parts

Meet the 3 pillars of sleep

Quality

Learn how much time you spend in each sleep stage: Light, Deep, REM & Awake. Deep sleep enables physical recovery while REM sleep helps with memory, thinking and creativity. Do you know how much time you spend in each ? Is it optimal ? Kira will help you improve and optimize these.

Duration

Circular looks at how much you have actually slept compared to your personal sleeping length needs. Circular also calculates the duration of disturbances during your sleep, and gives you a score on how efficiently you slept.

Circadian Rhythm

Science shows that sleep must follow a light/darkness cycle, be in line with your natural chronotype and that the more consistent you are with your sleep schedule, the better sleep you'll get. Kira makes recommendations that match up with your chronotype to achieve higher consistency.

Timing

Discover your Chronotype, a life changing tool

Chronotypes are linked to your internal clock and to your genes. They have a direct effect on the timing of your daily activities and your performance in doing them. Discover your Chronotype and the optimal times to do your activities.

Your day, as your chronotype orders it

00:0006:0012:0018:0024:00
Asleep

Your window, based on your own last two weeks.

Wake and rise

Light exposure here sets the whole day's rhythm.

Productivity zone

The hours your chronotype does its best thinking.

Caffeine window

Closes early enough to clear before your bedtime.

Movement

When training costs you least and returns most.

Wind-down

The ring nudges you here, adjusted for the day you had.

Waking up

A good waking experience for a good start of the day

Waking up in a light sleep stage helps to limit sleep inertia. If you are tired of waking up in a bad mood but would rather wake up with energy then Circular will help you.

Smart, noninvasive and silent at the same time. Circular can study your sleep and smoothly wake you up during the light sleep stage, without disturbing your surroundings thanks to silent vibrations.

Smart alarm · a window, not a time

06:38 woke you here
07:00 set
06:0006:3007:00
  • You setA time, and how wide the window before it can be.
  • The ring picksThe first light stage inside that window.
  • You feelSilent vibration on the finger. Nobody else wakes up.
  • You seeA wake-up score, and the minutes you gained.
How to read it

Nine numbers behind one score.

Each one is measured against your own baseline, learned over your first two weeks of wear. Tap any of them in the app for what it is, why it matters and what moves it.

  • Deep sleepPhysical repair. Clusters in the first half of the night.
  • REM sleepMemory, learning and mood. Longer stretches towards morning.
  • Real sleepTime actually asleep against time in bed.
  • DisturbancesHow often the night broke, and for how long.
  • TranquilityHow still you were — restlessness costs recovery.
  • Time to fall asleepMinutes from lights out to the first stable stage.
  • Circadian rhythmHow closely last night matched your own schedule.
  • Sleep debtAccumulated shortfall against your personal need.
  • Heart rate in sleepAverage, lowest point, and when it arrived.
  • BaselineEvery number above is read as a distance from yours.
Questions the ring answers

How much do you actually know about your sleep?

How much sleep should you get?
Your duration of real sleep?
The duration of your sleep cycle?
Your number of sleep cycle?
What is your optimal sleep schedule?
Your rem sleep duration?
How to lower your time to fall asleep?
Do you have sleep inertia or disturbed breathing at night?
What is the effect of your current sleep on your energy?
The routine

Biohack your way to better sleep

Make the most of your day by improving your sleep journey

1

Track your sleep each night and trends over time.

2

Understand your sleep and learn about the parameters that positively or negatively impact your sleep quality and how it correlates with your days.

3

Build better habits for better rest.

4

Wake up with energy with a silent & smart alarm clock.

What you are missing out on with a non efficient sleep

01

Immune system against illnesses and cardiovascular diseases

02

Productivity, cognitive ability and focus

03

Stress, mood and weight management

Questions

Before you wear it to bed.

More in the help centre.

Roughly two weeks. The ring spends that time learning your baselines — resting heart rate, HRV, temperature, how long you actually need — because a score against a population average tells you very little.

That is the reason the ring exists. Nothing on the wrist, nothing strapped to your chest, and the finger gives a cleaner optical signal than a watch pressed into a pillow.

The ring tracks blood oxygen and breathing rate through the night and can show patterns worth discussing with a clinician. It is not a diagnostic device.

No. The vibration comes from the ring itself, so the phone can stay in another room — which is usually better for the night anyway.

Yes, if you switch nap tracking on. Naps are scored separately and folded into your sleep debt rather than into last night's score.

No. Staging, the nine metrics, chronotype, the smart alarm and Kira's recommendations are included with the ring, permanently.

Next

Your physical activity also has a great impact on your energy

Learn how
Woman checking the Circular app while wearing the ring
Get to know yourself. Full circle.

Start with one night.

Wear it to bed tonight and read the morning.

Buy now Get a sizing kit
Woman checking the Circular app while wearing the ring
Get to know yourself. Full circle.

Start with one night.

Wear it to bed tonight and read the morning.

Buy nowGet a sizing kit