Well you could go all hypothetical on it but that's not necessarily worth it

Think estimate a ROI at a given average buy in and calculate your dollar per hour there.

Example: Average buy in= $20. You are able to play 10 tournaments in an hour for volume.

your Investment per hour will therefore be $200. If you have a 5% Return on Investment, then you will be making 10$ an hour.

If you want to go really crazy, you can add in approximate rake-back

at 10 tournaments with an average rake of 10% of your buy in you will have invested 20$ in rake. If you have 20% rake-back, you'll walk away with an additional $4/hr.

Basically, pick an average buy in, pick a hypothetical number of tables per hour, pick a hypothetical ROI and BAM you have yourself a bunch of numbers that mean nothing if you can't achieve them like me

You'll have to ask people what a realistic ROI is but as far as I know, in anything beyond the single digit stakes, 5% is a strong player (you are owning that limit.) Don't set your hypothetical ROI to higher than 5% unless you are extremely optimistic