It really all depends on your weight, goals, and daily nutrient needs are. Whatever your daily maintenence number of calories is, a certain amount of those calories should come from healthy fats (olive oil, fish oil, flaxseed oil, fats from nuts, avacados, and some animal fat). Again, that amount depends on your goals. Whether you are eating in a deficit, surplus, or maintenence will decide how many of your cals should from fats. From there, divide by 9, and thats the total amount of fat grams you should have a day, since one gram of fat is 9 calories burned. Then, have an equal number of saturated, monounsaturated, and polyunsaturated fats. I think that's about it...