Ionic3: How to get amount of data transferred?

Hi, as an addition to synchro process in Ionic3 app I need to calculate data sent and received by the app and log it into the database. What I’ve discovered on the Web Ionic3 does not offer dedicated plugin to serve that. The suggested solution would be to calculate the content of template and attachments. Does anyone of you have some experience in it? Would you share? Would be great!