How do I measure weight of all objects within the frame using Yolo?

[freymeyer]

I heard about training the dataset that consists of an object's measurement (length and girth) and their weight as well and implement machine learning as we want Yolo to detect all (for example an explant)

Then, estimate their weight afterwards using only OpenCV and Yolo.

How do I implement it?

And, what formula could I use to determine the weight by using height, width and girth?

And if this is possible to ask, how do I train the data of explants and let Yolo know what their determined weight after?