Typical googling tells me a cup of white rice has ~200 calories, but the bags of white rice I purchase tell me a quarter cup of dry rice has 150 calories (Jasmine, in this case, but others have been about the same), which would mean a cup would have 600 calories.
Which is it? And what's the reason for the discrepancy?
I’m afraid you may have misunderstood some results (or they were unclear in their descriptions).
A ballpark number for rice volume is that cooking white rice will give you about triple the dry rice volume.
So let’s look at your data: 1/4 cup of raw rice makes 3/4 cups of cooked rice. The calories don’t change, assuming that you add just water and don’t pour away a significant amount of starch. So you still have 150 kcal for 1/4 cup of dry or 3/4 cups of cooked rice.
If 3/4 cup cooked white rice has 150 kcal, one cup of cooked white rice is roughly 200 kcals - which is exactly what you found out.
That depends on whether you're talking about cooked or uncooked rice. 1 cup will cook to 3 cups. 3/4 cup will cook to 1 cup. 1 cup uncooked rice will be around 600 calories. 1 cup cooked rice will be around 300 calories.
