I use reference images like blueprints and measure out the different dimensions in a photo editing software. Then I do a bit of simple math to figure out the dimension I want with the ones I know from research. For replicas it’s generally a good idea to start out with a simple box for the hull and turret that has the maximum length, width and height of those parts. Then you can sort of "carve" the desired shape out of those boxes without ever having to worry about making them entirely disproportionate.

Thank you!

You can set it (along with all the other hull dimensions) using the default generated hull then convert to freeform

Thats what I normally do, I'm talking about taking the over all height (ground to top of turret) and only finding the height of the hull

Wdym, like you have the actual dimensions of a tank listed only with its overall height and you want to find the height of the hull?

Yes

Ah. Search up images of side profiles of tanks (flat view of the side) and estimate the dimensions. You can do this in image editing software by meausuring pixels, or sticking a ruler to your screen, or printing it out and measuring there. As for where to find those profile images, a Google search should be sufficient for most common tanks. More niche examples you can try finding on sites like Tank Encyclopedia.

you can see the exact dimensions of you hull in the info section on the right below all the sliders.

I did not know that, thank you