How to find how much VRAM is needed for a scene?

I’m gonna get a new gpu soon and I need to find out how much VRAM I would need for some of my scenes. Is there a way to find this out?

Thanks in advance!

first go to much VRAM you can efford ! R9 390 is a good choice ! if you want to test a specific scene you must have a GPU and install GPU-Z and check VRAM usage while rendering .