Calorie Intake to Lose or Gain Weight

The Calorie Intake to Lose or Gain Weight calculator computes the number of daily food calories one should consume to reach a weight goal based on the person's weight, height, age, gender and a level of activity.

INSTRUCTIONS: Choose units and enter the following:

• (W) Weight
• (H) Height
• (Age) Age
• (G) Gender
• (AR) Activity Factor
• (lb) Weight Change Desired (minus pounds for loss, plus pounds for gain)

Calorie Intake to Lose/Gain Weight (kcal/day): The results are returns in food calories per day (kcal/day).  However, these can be automatically converted to compatible units via the pull-down menu.

The Math / Science

The Calorie Intake to Lose/Gain Weight calculates the number of calories recommended based on factors such as weight, height, age, gender, and level of activity to lose/gain a number of pounds in one week. This calculates the number of daily calories necessary to gain/loose/maintain your weight.  This formula uses the Harris-Benedict principle. This equation add/subtracts 500 calories for each lb you wish to lose/gain in a week. It is important to note that it is recommended that you not lose more than 1-2 lbs per week. It is also not recommended that calorie intake drop below 1,200 calories per day. 

This calculator is a great way to get a look at the big picture but it is important to understand that what you eat as well as how much you eat matters.
To better understand calories for weight loss formula and the ways that calories from fats, proteins, and carbohydrates differ, refer to the references below.

References

SuperFat: The Calorie Deficit Diet Myth
Harris-Benedict Equation
Calories for weight loss formula