A new research has revealed that WhatsApp voice calling could be costing you a small fortune .
WhatsApp calls, which require a mobile or Wi-Fi internet connection, allows users to make free phone calls to WhatsApp contacts, wherever they are in the world, the Daily Express reported.
The Android Pit test has revealed that WhatsApp voice callings, which have been available on Android since the start of the year but were only recently added to the iPhone app, uses 1.3Mb of data per minute.
Chatting away at a rate of 1.3Mb of data per minute will burn through a 500MB monthly data plan in just 6 hors, which is equal to 11 minute of call-time per day.
However, by contrast, instant messaging and Voice over IP app Viber claims to use 240Kb per minute during phone calls.