Need help calculating protein, fat, carb intake.Doin it ryt?

Using the following example from http://www.myfitnesspal.com/topics/show/819055-setting-your-calorie-and-macro-targets -this link...I have calculated my protein, fat and carb intake per day for me...

the example is :

For example, say someone is 150 lbs with a BF% of 20% on a 2,000 calorie target. Their macros in grams would be:

Protein: 1 x 150 x 0.8 (LBM) = 120g x 4 calories = 480 calories divided by 2,000 (calorie target) = 24% - round up to 25%
Fat: 0.35 x 150 = 53.5g x 9 calories = 473 calories divided by 2,000 = 24% - round up to 25%
Carbs: balance of 50%

and what I have calculated is-

Protein: 1*120*0.5 (LBM) = 60 * 4 calories (still don't know where this amount of calories came from) = 240 / 1200 = 20%

Fat: 0.35*120 = 42 * 9 calories (don't know how 9 calories) = 378 / 1200 = 31.5% -round up to 32%

Carbs: balance of 48%


Please tell me are these calculations correct? And I am knew to this so I really don't know anything about it...so wanna know How do we use these percentages to find out how much protein, fat and carbs are to be taken a day?

PLEASE HELP!