WhatsApp is quick to say its calling feature is free, even between countries, as it uses a smartphone’s internet connection rather than a plan’s voice minutes.
However, WhatsApp also says 'data charges may apply', so how free is free?
WhatsApp calling has been available on Android devices since the start of the year, and have recently been added to the iPhone app.
According to a recent test by AndroidPit, the app uses 1.3Mb of data per minute when making a phone call, regardless of operating system.
This means a 500Mb monthly data plan will last just six hours, or 11 minutes of call-time per day.
However, this also doesn't take into account that smartphone users are increasingly using their phone to stream video content, play music, and engage with other apps that require an internet connection.
While WhatsApp's high data consumption doesn’t impact a user when they have an unlimited Wi-Fi connection, it’s an entirely different story when they're using a restricted 3G or 4G data plan.
Unlimited data plans are rare, and when available, are very expensive in comparison to the more affordable 1Gb or 500Mb plans.
In order to get the above results, AndroidPit made a series of WhatsApp calls and measured data consumption with two tools, the figures given by the Android system itself and Data Monitor, an app that measures data rates. The average of both figures is the final result.
The test produced results that range between 800 KB to 1.3MB with an average of 960KB per minute, and the Android system offered a lower average of 600KB per minute. Even if you average out both figures, it averages about 800 KB/minute.