Features/Live measurements

When you want the number now, not tomorrow morning.

Most of what the ring reads, it reads while you are asleep. Live measurements is the other half: hold still for about 40 seconds and watch heart rate, variability, oxygen and breathing arrive in real time, with the signal quality shown honestly rather than smoothed over.

LiveRing 78%
Heart rate 60bpm
Resting zone

Last 30 seconds

This reading
Variability68 ms
Oxygen · SpO₂98%
Breathing rate13.6 / min

Signal steady. You settled into your resting zone after about 11 seconds.

40 seconds

The first seconds are noise. The app says so instead of hiding it.

Heart rate through one reading · 40 seconds

60bpm at the end · your resting range 58 to 66

Settled after

11s

Samples in range

22 of 30

Started at

78 bpm

0s13s27s40s
Your resting range Measured heart rate First 11 seconds · still stabilising

Take a reading straight after climbing the stairs and the first numbers will be wrong. The app holds the result back until the signal is steady, and tells you how long that took rather than presenting the whole reading as equally reliable.

Four cards, one anatomy

What arrives in a single reading.

Pulso
60bpm
Heart-rate variability
68ms
Oxígeno en sangre
98% SpO₂
Respiración
13.6/ min

Every card carries the same three parts: what it is, the number, and one piece of context. No card shows a figure twice, and SpO₂ keeps its subscript.

Five zones

Where this reading sits, against your own maximum.

RestingBelow 60% of max
Light60–70%
Moderate70–80%
Hard80–90%
Maximum90%+

Zones are drawn from your own measured maximum, not from a formula based on your age. The reading above sits in Resting, which is what you want when the point of the measurement is a baseline rather than an effort.

Starting a reading

Two screens before the first number.

01The disclaimer, on its own

Live measurements are for wellness, not diagnosis. That sits alone on one screen rather than buried in a list of tips, because it is the one thing you should actually read.

02Then everything practical

Battery, what affects accuracy, and the reminder to stay still for about fifteen seconds — merged into a single screen instead of three separate pop-ups.

03Hold still and watch

The reading builds live. You can leave at any point; a partial reading is discarded rather than saved as if it were complete.

When it will not read

Four states that say no, clearly.

Ring not connected
No Bluetooth link, so no reading is attempted and nothing is estimated in its place.
Battery too low
Live readings draw hard on the battery. Below the threshold the app asks you to charge first.
Weak signal past 30s
Usually fit or movement. The app suggests the fix rather than producing a confident wrong number.
Ring removed
The reading stops and is dropped. Nothing partial is written to your history.

Live measurements are for wellness and general fitness. They are not a diagnostic tool and do not replace medical equipment or advice.

Questions

Before you take a reading.

More in the help centre.

About 40 seconds end to end, with the first fifteen spent letting the signal settle. Sitting still for that stretch is the single biggest thing you can do for accuracy.

Because you moved to start the reading. Heart rate takes several seconds to come back down, which is why the app shows the settling period rather than averaging it away.

More than passive tracking, yes — the sensors run continuously and stream to your phone. A handful of readings a day is unnoticeable; dozens will shorten the week.

You can, and the zone read-out is built for it, but movement costs signal quality. For a session, start a sport session instead — it is designed for movement and logs the whole effort.

Completed readings are, with a timestamp and a signal-quality mark. Interrupted ones are discarded rather than stored as partial data.

No. Live measurements are included with the ring, permanently.

Siguiente

A forty-second reading of the rhythm itself

See ECG & heart rhythm
Woman checking the Circular app at home while wearing the ring
Conócete a ti mismo. Círculo completo.

Any moment you are curious, it will tell you.

Forty seconds, four numbers, and an honest read on how good the signal was.

Buy now Read the science
Woman checking the Circular app at home while wearing the ring

Conócete a ti mismo. Círculo completo.

Any moment you are curious, it will tell you.

Forty seconds, four numbers, and an honest read on how good the signal was.