What’s the ratios for foundries to saturate a full belt of all the colors?

[tgirl swag]

My brain is too small to figure it out with the productivity bonus and crafting speed

[Hurkyl]

If you mouseover a building look at the detailed info, it shows the throughput.

[Doomstrike53]

That number doesn't take into consideration the productivity bonus. You have to add that yourself. Unfortunately that may not be good enough because I did the math and figured 8 foundries smelting iron plates from iron ore on Nauvis would be required to fill a blue belt. 3.75/s + 1.875 productivity bonus = 5.625/s. 5.625 *8=45/s, a blue belt's worth. When I actually built it, it wasn't enough to fill a blue belt. I'm not sure what to think now.

Edit: Ok, I may have been wrong about it not taking productivity into account. Putting a productivity module does in fact change the number. I'm going to test it again using the actual number this time and see if it works.

Edit 2: I stand corrected. 3.75*12=45/s, which does fill a blue belt. 12 foundries are required and can be fed from 2 foundries melting iron ore, both of them with modules (2 level 2 speed and 2 level 2 efficiency).