The Economic Efficiency UI Planetary Annihilation mod is very helpful for getting a quick overview of how your economy is doing.

Economy Ratios

Economic Efficiency Mod

Metal Ratio:
formula : (metal income / metal outcome) x 100
This value shows relatively how much you spend regarding how much you gain.
50% means you lose twice what you gain
100% means you lose as much as you gain
200% means you lose half what you gain

Energy Ratio:
formula : (energy income / energy outcome) x 100
50% means you lose twice what you gain
100% means you lose as much as you gain
200% means you lose half what you gain