screen recording size
I want to record my workflow to then later edit down into tutorials. I'm using an external 4k monitor with my M1 MacBook Pro which is 3840x2160 resolution. How many gigabytes am I looking at per hour of Screenflow recording? I'm already maxing out my 512 GB SSD.
I would think there'd be a handy chart somewhere...
I may be wrong but I don't think there's any simple chart like you are seeking. I've made several videos which have the same screen size and almost (within 10 seconds) the same length of 10 minutes. The sizes of each recording was wildly different. In my case I'm certain it had to do with how much "movement" I had on the screen. More static videos were smaller, those with more movement were larger.
Bob McCarter the codec is variable bit rate to maintain the best quality based on the content being captured. As Mathew notes it has to do with the movement and complexity of the screen captured. You'd have to run a test mimicking the busiest part for a few minutes and estimate from there (and this would only be an estimate so you should allow for much more headroom). You should always maintain at least 20% free drive space (including after recording) for the OS and ScreenFlow to use for temp data.