Measure your rice in grams first. Lets say 1 serving is 40 grams and you want to cook 4 servings, then multiply 40 x 4. Your 4 servings is 180 grams total. Cook your rice. After you cook it, weigh it again. If your cooked rice is now 320 grams (random number here, it will be more due to absorbing the water) just divide 320 by 4, that is 80. That means 1 serving is 80 grams. So whatever the macros are for 40 grams are now the macros for 80 grams. Obviously you may not get nice, even numbers like the ones I used as examples, but that is the process.
