I'm trying to find out approximately the data usage it takes to make a voice "phone call" using WhatsApp.
To this point, I've scoured the WhatsApp help itself (no info), and looked at the "on topic" guidance at WebApps.SE, ProWebmasters.SE, and here at SU. This doesn't look a perfect fit for any SE site, really -- which surprises me!
Still, there are a number of WhatsApp questions here on SU, and it feels like this is my best hope. Could a mod or other high-rep user give me a steer on this? Thanks!
Background: this is for connections in southern Africa where options are few, but where WhatsApp works better than internet dongles, bizarrely enough. The packages are based on x amount of data transfer per month, though: thus the point of my question. I'd like to be able to guesstimate what kind of hit on data allowance using voice chat would make.