Smartwatch specs, translated

Smartwatch listings are dense with abbreviations, and only a few of them affect daily use. Here is what each actually means.

Display: AMOLED vs LCD

AMOLED lights each pixel individually, so blacks are genuinely black and an always-on face costs less battery. LCD uses a backlight — fine indoors, harder to read in direct sun. In Indian daylight the difference is noticeable, and it is the spec most worth paying for.

Bluetooth calling

The watch has its own speaker and microphone and answers calls routed from your phone. Useful when your hands are busy or the phone is in a bag. It is not a SIM — the watch cannot make calls on its own, and the phone still needs to be in range.

SpO2 and heart rate

SpO2 estimates blood oxygen from light passing through your skin. Heart rate works the same way. Both are useful for spotting trends over weeks; neither is a medical device, and a single reading should not worry you. Watches consistently over-read during exercise, when the sensor is moving.

Water resistance: IP vs ATM

• IP67 — dust-tight, survives immersion in a metre of water briefly. Fine for rain, hand-washing and sweat. Not for swimming.
• IP68 — slightly better immersion tolerance. Still not a swimming rating.
• 5ATM — genuinely rated for swimming. If you want to swim in it, look for this rather than an IP number.

Battery claims

Advertised battery life assumes the always-on display is off, brightness is low and notifications are sparse. Halve the number on the box for realistic daily use with an always-on AMOLED face. A watch quoting seven days will usually give three or four in practice.

What does not matter much

Sport mode counts are largely decoration — a hundred modes mostly means a hundred labels on the same timer. Included spare straps are genuinely useful, though, and cost almost nothing to add.