How many fat grams are in an egg?

Well, it depends. How big of an egg? Eggs are classified from 38g (small) to 63g (jumbo).

I normally buy large (50g) or extra large (56g) eggs, so I will give you the data for those:

The egg contains 72 or 80 calories, and 5g or 5.5g of fat. Of that fat, 1.55g or 1.74g are saturated, 1.95g or 2.14g are monounsaturated, and .68g or .76g are polyunsaturated.

Just to give you far more information than you were looking for, a small egg contains 3.78g of fat in its 54 calories, and a jumbo egg contains 6.26g of fat in its 90 calories.

All of this data comes from: http://www.nal.usda.gov/fnic/foodcomp/search/ which is awesome for finding out exactly what is contained in what foods.