This is why you have to be careful with volume measurements. How you cook and how you measure can yield very different results. If the package says it makes 5 servings, I assume that is correct. My volume and the company's volume may differ though. So if it makes 5 servings I would divide it out into 5 and figure that 1/5 would be the 160 cals stated.
And rice is roughly in the 160 range for a 1/4 cup dry serving depending on kind. The last time I made rice it was with lentils in the slow cooker and a cup of that mix turned into four cups cooked. And rice always at least doubles. So it is not that far off for a cup, especially if you fluff before you measure and do not pack as much as you can in the cup.
-google first. ask questions later.