Items per second info on machines.

[ssilk]

I think there is also https://mods.factorio.com/mod/MaxRateCalculator and https://mods.factorio.com/mod/RateCalculator which goes also into that direction. Eventually also https://mods.factorio.com/mod/helmod

[tolomea]

Thank you @eradicator and @ssilk
I was aware of Helmod and Factory Planner already, inline with some of the comments above I feel that at my level they are taking over a bit too much of the puzzle, mostly I just want to get rid of the repetitive error prone math. The other 3 recommendations all look good in that regard.