AR App to measure volumes of 3D objects in Unity

I'm trying to develop an AR application that is able to capture objects and then measure their volume. First I was planning to create it for Cube-shaped objects such as boxes, mobile phones. What I planned to do after research was to create a bound box once the object is captured by the camera. I was looking all over for tutorials, forums to find a good headstart for the project, but could not find any. Does anybody can help me to get an idea of how to do this or provide me a reference to follow up, that would be really helpful. I'm very new to AR development but not to Unity.

Appreciate any suggestion. Thanks