Fitbit Ionic showing energy measurement. (Business Insider/Tony Yoo)

Fitbit has launched its first-ever general-purpose smartwatch, the Ionic, but the sophisticated device has one critical weakness that will put off many Australians (and many non-US customers).

The watch’s software, much like its predecessors, does not support showing energy in metric units – kilojoules. The measurement is only ever shown in the non-SI unit of calories.

While calories is used in the USA, and by some on calorie-counting diets, it’s not widely used by Australian consumers. The Australian government and education system officially use the metric system.

Nutritional information table on a can of Coke Zero. (Business Insider/Tony Yoo)

With health advice like government guidelines and nutritional information tables for food and drinks all shown in kilojoules, the watch becomes useless for Australians unless they’re willing to do the mental conversion every time – which defeats the whole purpose of having a powerful computer on your wrist.

And, in case you were wondering, one calorie equals 4.18 joules.

Fitbit Australia confirmed to Business Insider that a kilojoule display is not available on the device.

Screenshot of Fitbit app’s units settings. (Business Insider/Tony Yoo)

While Australians will be stuck with an archaic measurement for energy, the Fitbit app does allow the use of metric units for length (cm, km), weight (kg), water volume (ml) and swimming distance (m).

For Australians that are less concerned about health and more interested in contactless payments, Fitbit Pay revealed this week that it signed three of the Big Four banks – Commonwealth, NAB and ANZ – which is more than both Apple Pay and Samsung Pay.

The Fitbit Ionic is selling for $449.95 in Australia and features fitness, heart and sleep monitors, as well as music storage and ability to alert for phone calls. The US company claims the device, which will be in stores worldwide next month, has a five-day battery life.

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