# How do I determine the utility of level combinations from different attributes?

Do I understand it right, that in order to determine the overall utility of the combination of A1L1 & A2L1 I have to calculate A1L1 + A2L1 + A1L1*A2L1?

Lets say I have one attribute (A1) with different car brands (Brand A , Brand B, Brand C) and an attribute (A2) with different colors (red, blue, white).

In a multinominal logit model I received for Brand A an effect of 1.80, for color red I received an effect of 0.41 and for the interaction of Brand A * Color red I received an effect of 0.46. Does it mean that the utility of a "red Brand A car " would be 1.80 + 0.41 + 0.46  = 2.67? And not just the effect of the interaction term Brand A * Color red= 0.46?

And if so, do I have to calculate this with the effects I receive in the model output or rather with the utilities (zero-centered differences) which I receive when I click on utility report?

So in my case it would be 113.84 + 26.28 + 29.03  then and not 1.80 + 0.41 + 0.46 ?
related to an answer for: How to interpret interaction effects?