I know that when a label says 0 carbs for a serving of something, it could actually contain up to 0.9 carbs. Am I correct in assuming that's true for all amounts? For instance, something labeled 2 carbs per serving could actually have up to 2.9, right?

Safe bet to think so, Mr.Mel. Hard to tell with packaged/processed foods. They cheat!!

Lesle

I think so. It also helps to read the ingredient list to make an educated guest. For instance, salad dressing should start with oil, water, eggs, vinegar and not have any form of sugar until at least the fourth ingredient.

I think they have to follow regular rounding principles.
So
0.0 to .4999999999999 is 0
0.5 to .9999999999999 is <1
1.0 to 1.4999999999999 is 1
1.5 to 2.4999999999999 is 2
2.5 ro 3.4999999999999 is 3
etc

hope this helps

I don't know the laws for fat calories, but if you can find a label that has fat calories NOT at a multiple of 5 (or even 10), please let me know what that product is so I can peruse the label and check their math.