The website for Bob's Red Mill, which is the brand I buy, lists a serving size as 1/4 cup/40 g. I'm assuming this is dry. Calories are 170. In the microwave instructions, it says to use 3/4 cup of water to 1/4 cup of oats. You could do this and see how much it makes cooked, and then as long as you use the same ratio (3 parts of water for 1 part of oats) you can assume that a serving of that size is 170 calories.
As for pasta, the usual serving is 2 oz dry. I weigh mine and cook it separately. Weighing accounts for all the weird shapes that prevent accurate measuring.