Inaccurate Data

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Give it a week. Your Voltra spends the first seven days building a baseline for you, and readings move around while it does. Judging accuracy on day two is judging it before it has anything to compare you to.

This covers the Voltra Pro and the Voltra Air. After the first week, the most common cause of odd readings by a long way is fit. Everything else on this page is worth checking second.

Measured or estimated

Some of what you see is read directly off the sensor. The rest is worked out from those readings plus your profile. Knowing which is which explains most of what looks wrong.

Estimated figures are for spotting your own trend over weeks. They aren't lab measurements and comparing them to someone else's numbers won't tell you much.

The first seven days

Wear it as much as you can for the first week, including overnight. During that period:

• Sleep scores will swing more than they will later.
• Resting heart rate settles as it collects more overnight readings.
• Trends aren't meaningful yet - you need a baseline before a change means anything.

If you take it off for two of the first seven nights, the baseline takes longer. It isn't broken, it's just short of data.

Heart rate looks wrong

Fit, first

The sensor reads light through your skin. A gap means a bad reading. It should sit a finger's width above the wrist bone, flat against the skin, snug enough that it doesn't slide when you turn your wrist. See sizing and fit.

During exercise

Wrist sensors struggle with anything involving grip or impact - weights, boxing, rowing, press-ups. The wrist flexes, the sensor lifts, the reading drops out or spikes. Move it an inch or two further up your arm and tighten it a notch before you train.

Cold hands

Cold reduces blood flow to your wrist and the sensor has less to read. Readings in winter, first thing, or straight after being outside are the least reliable ones you'll get.

Tattoos

Dark ink over the sensor area absorbs the light the sensor depends on. There's no setting that fixes this - the only thing that works is wearing it somewhere with less ink.

Sleep looks wrong

• A whole night missing. The device was off, flat, or too loose to read continuously.
• It thinks you were asleep when you were reading in bed. Lying still with a low heart rate looks a lot like sleep. Most trackers get this wrong.
• It missed a nap. [Confirm whether naps are detected.]
• The times are shifted. The device takes its time from your phone. After travelling, check your phone is set to update time automatically and force a sync.
• Stages look implausible. Sleep stages are estimated from movement and heart rate, not brain activity. Treat the total and the trend as useful and the exact stage split as indicative.

Steps look wrong

Step counting looks for a repeating arm swing, so it over and under counts in predictable ways.

• Counts you didn't take: driving on rough roads, washing up, clapping, DIY.
• Missed steps: pushing a trolley or a pram, carrying something, hands in pockets, walking with a stick.
• Cycling barely registers as steps, because your arms aren't swinging. That's expected rather than a fault.

A count that's low across a whole day is more likely a missed sync than a missed walk. Force a sync before assuming it's lost - see syncing problems.

Calories look wrong

Calorie figures come from your heart rate and your profile, so they're only as good as what's in your profile. Check your date of birth, sex, height and weight are right and up to date. Every wearable and every gym machine uses a different formula, so two devices will never agree on calories and neither is the truth.

It doesn't match my other tracker

It won't, and neither of them is lying to you.

Two devices worn on different wrists, sampling at different rates, using different algorithms, will produce different numbers for the same person doing the same thing. That's true of every brand against every other brand. The same applies to gym equipment and chest straps - each uses its own method and its own assumptions.

What matters is consistency within one device. If your Voltra reads the same way under the same conditions, the change it shows you over a month is real, even if the absolute figure differs from something else you own.

Check your profile

Several figures are calculated rather than measured, so a wrong profile produces wrong numbers with no error message. In the Q Watch Pro app, open Me, then Profile, and check your date of birth, sex, height and weight. Update your weight when it changes meaningfully.

When it's actually a fault

Most of this page is the difference between an estimate and a measurement. These are different, and worth reporting:

• Heart rate reading zero, or stuck on the same number for hours
• No readings at all despite the device being worn, charged and synced
• Readings that were fine for months and changed suddenly rather than gradually
• Step counts of tens of thousands on a day you barely moved

Message us with your order number, what the reading said, what you were doing and roughly when. A screenshot of the day in the app is the fastest way for us to see it.

One thing worth saying plainly

Voltra is a wellness product, not a medical device, and nothing it shows you is a diagnosis. It's built to show you your own patterns over time. If a reading worries you, or if something feels wrong regardless of what the app says, speak to your GP rather than to your tracker.