Is there a chart to convert .045 to .035 ipm.

I was welding up a receiver hitch for my pu. It has the 2 1/2'' receiver.
I took out my iphone and went to the new Miller app, it said 29volts 390ipm .045.
I did not have any .045, so I made the .035 work at 525 ipm, it was not quite enough, but worked.
So is there a chart I could use to get ipm right the first time?
Good Luck,