I am on a 1400 calorie diet, how many grams of fat should I eat?

Less than 50 gm. Calories from fat should be fewer than 30%. You should aim for about 45 gms of fat per day or lower.
I never liked math. Ok here we go. To stay heart healthy don't eat more than 30% of your calories from fat. So 1400 x .30 = 420 or less of your calories should come from fat. Now there are 9 calories in each gram of fat. So 420/9 = 46 or less grams of fat is what you should shoot for. Also no more than 1/3 of your fat calories should be saturated fat. So 46/3 = 15 or less saturated fat grams. Phew...I'm tired.