Caloric Needs Formula From Prevention

There are several ways to determine your daily calorie needs.
Many health clubs offer metabolism testing for about $50.
You just breathe into a device that calculates your calorie requirements.
Small studies say these tests are fairly precise, but when I tried one, there was a 400-calorie discrepancy between it and the more sophisticated, more expensive lab test.
That might have been a fluke, but it's also why I suggest that you start with this good old-fashioned formula for women.
It's free, easy, and nearly as accurate as the lab test:
[10 x weight (kg*)] + [6.25 x height (cm*)] - [5 x age (yr)] - 161.
Now multiply that number by your activity factor below.
(If you don't want to do the math, use our Calorie Calculator.)
Inactive: Just walking to and from the car = 1.2
Lightly active: Daily 30-minute stroll or 30-minute brisk walk 1 to 3 days a week = 1.4
Moderately active: A 30-minute brisk walk 3 or more days a week or a non-desk job, e.g., cashier = 1.6
Very active: 30 minutes of exercise like running 3 to 5 days a week or an active job, e.g., waitress = 1.7
The result is the number of calories you need daily to stay at your current weight.
To lose a pound a week, you need to either cut out or burn off 500 calories a day (1 pound = 3,500 calories).
*To convert, multiply pounds by 0.454 and inches by 2.54.