How to Determine Your Calorie Needs

How to Determine Your Calorie Needs

Determining your body’s total dietary energy needs takes some math – so get a calculator. This method of determining your calorie needs is almost as easy and accurate as logging into a research lab and subjecting yourself to scientific scrutiny by a white-covered nerd with a case and stopwatch.

  1. Estimate your basic energy needs.
    Multiply your current weight (in pounds) by 10 if you are a woman or 11 if you are a man. Or use the formula in the table below, which determines your age factors in addition to your gender.
    For example: Sue is 45 years old and weighs 155 lbs. She calculates her BMR like this:
    155 pounds 2.2 = 70.45 kilograms
    70.45 kilograms x 8.7 = 612.92 calories
    612.92 calories + 829 calories = 1441.92 calories
    So Sue’s basal metabolic rate — or the number of calories her body needs while at complete rest to function — is roughly 1,442 calories.
    If you determine Sue’s basal metabolic rate using the abbreviation method, her needs would be around 1,550 (155 lbs x 10 = 1,550) – slightly higher than the full calculation, but still in the same ballpark.

2. Determine the value of your activity factor.
How active are you? Find the description in the following table that best suits your lifestyle. If you have a desk job but fit in with a dose of daily exercise (at least 30 minutes), consider yourself in a light or moderate category.

3. Multiply your basic energy needs by the activity factor value you specified in step
Using Sue as an example, she multiplied her BMR of 1,442 by 0.3 because her activity level is light — running after her kids, looking after the house, and taking a two-mile morning walk with her neighbors every day. Sue needs 432.6 calories for her activity level.
1,442 x 0.3 = 432.6 calories
4. Determine how many calories you need to digest and absorb nutrients.
Eating food actually burns calories. Digesting food and absorbing nutrients consume about 10 percent of your daily energy needs. Add your BMR and activity calories, then multiply the total by 10 percent.
Calculating Sue’s caloric needs for digestion and absorption looks like this:
1,442 calories + 432.6 calories = 1874.6 x 10% = 187.5 calories

5. Total your calorie needs.
Add your BMR, activity and calories you need for digestion/absorption to get your total caloric needs – the number of calories you need to maintain your current weight.
To maintain her current weight of 155 pounds, Sue calculates her total calorie needs as:
1442 calories + 432.6 calories + 187.5 calories = 2.062 total calories