Hey, Cara. I could not post this as a comment because it was far too long. But I wanted to let you know this info tonight before I went to bed (or today for you :) ). If you don't mind me posting it (tell me if you do), it may also be helpful for others to see how it's done. And don't be intimidated by the information below. It's really not complicated, but I just wanted to make sure I covered everything I could think might pose an issue for you or anyone else.
Okay, calculating caloric intake and expenditure is a two-step process really (but a simple one if you go to the sites and use the easy calculator). I don't know if I explained the process well initially. That may have been what mucked poor Cara up. So I'll try to do a better, more thorough job here.
First you go to the BMR calculator page at http://www.bmi-calculator.net/bmr-calculator/. I don't have a link to this one (though my link has a link :) ). This is different than your BMI, so don't even think about your BMI while you're doing this.
I cannot recall how tall Cara is, but I entered (guessed) 5'5 since I figure she is somewhere thereabouts (and that is about average--at least for Americans). (If your height is wrong (sorry :( ), you can go to that site and enter your height and other info). So what you do when you get there is enter your height, weight, and age (and you can even use the metric system--you can click a simple link to do this right above where you enter the info). I used the Imperial (US-used scale to make it easier for me--after I converted her kilos to pounds). After you enter this info and hit 'Calculate BMR', your BMR should be in red right above the calculator. (By the way, this is the area where you can change your weight to your goal weight and such to see what you will need to do to maintain when you get to that point).
Next, you go to the Harris-Benedict Formula page, which is where the real action happens (that is my Caloric Intake Formula Link on the right--it's a whole different page than the BMR page). Remember to use the BMR number you just calculated and not your BMI or any other number. So what I did with you was take Cara's BMR number and multiply it by the sedentary activity number of 1.2. I used the sedentary activity level in calculating this (I do this with mine almost every time to see what I could technically eat with the least possible activity--but you can change this to more accurately reflect your lifestyle if you do it again).
So, again, multiply your BMR--the number in red from the BMR calculator website above--by one of the activity numbers on the Harris-Benedict page. It is really as simple as this last sentence. For Cara (at 5'5" tall, which may or may not be her height), I got 1874.838 when I multiplied her figures by the sedentary 1.2 number (on my trusty pink calculator). Of course, you can do that part by hand too--and there is a formula for the whole deal that I can give you if this still doesn't work or make sense. Good luck everyone!