This might help....
Example: For a 16 foot cattle panel, 8 feet wide, it would be 6.13 feet tall in the middle.
There are a number of considerations to think about. If you live in a snow state, you want a higher, narrower dome to shed the snow. If not, the snow will pile up on a flatter dome and collapse your structure. If you don't have to worry about snow, then you can spread out the cattle panel more and have more usable space for the chickens, for example, but you would have less headroom for people.
For people in snow states, I have seen them build up a base wall, like using pallets about waist high, and then spreading out the dome but adding a brace(s) along the top for snow load protection.
EDIT: For some reason, the picture I copied does not seem to show in the post, so here is the
link to the graph.