New Delhi: 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 AndroidPit 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.