I am a college student and although I have been counting calories as best I can, I often have to eyeball it. This is because I eat dinner everyday and often lunch in a cafeteria where I cannot weigh anything, and the cafeteria actually does have calorie counts for main entrees, but it is often things like x amount of calories per 4 ounces, which kind of leaves me hanging and I TRY to estimate how much 4 ounces would be but it's not easy. Problem is that I can't measure in the cafeteria, and that is a great deal of my food intake. I will be home in a month and over the summer I can measure my food, and when I come back in August I should be able to buy a food scale (I have almost NO money right now!) so I can at least measure my food I eat outside the cafeteria such as cereal, but for now I'm forced to eyeball it, which I know isn't good, but, at least with the cafeteria, it's unavoidable.
Now, I've been eating a lot BETTER foods... my dinner tends to be a glass of milk, a salad with a LITTLE bit of thousand island (making sure to go as light on the dressing as possible), often a little brown rice and/or some tasty veggies, so those don't worry me too much. What worries me is having the main entrees. I always go for the ones that aren't super high in calories and are both healthy AND taste good but I'm still worried about figuring out. I've tried rounding up for safety, like if I think "That's probably about 2-3 cups of rice" going with the 3 cups in case, but is there anything else I can do for good measure (hahaha a pun!), since I can't measure my food?

I'm definitely eating much more reasonable portions now than I used to, but I'm still worried I guess.