How to disable automatic scaling on features with Counts and Amounts (Size) style

[RaiTokuhisa]

In ArcGIS Pro, when using Proportional Symbols, you can set the units and what it represents (e.g. "US feet" and "Radius" for a tree). This makes the symbology independent of zoom scale. What is the equivalent on ArcGIS Online? Right now I have a map with a tree layer that shows a cottonwood the size of the entire Des Moines metro area when I zoom out to the state of Iowa. 

[JamesPoeschel]

I don't think its possible in the same way as in PRO.
I think the equivalent is the size sliders; you can restrict the max size in the slider so that the symbol is never super big. But the downside is that when you zoom in, it will still be small. But it's still useful to find a middle ground.

Another work around is to restrict the visibility range of that layer and have a duplicate layer with more appropriate symbology kick in when going past a certain zoom level. 

Depending on your data you could also just do unique values, and make all the symbols fixed size and resemble a color and size symbology.