How to Determine Your Calorie Needs - dummies

# How to Determine Your Calorie Needs

Determining your body’s total dietary energy needs takes a bit of math — so grab a calculator. This method of determining your calorie needs is easier and almost as accurate as checking into a research lab and submitting yourself to scientific scrutiny by a white-coated nerd with a clipboard and a stopwatch.

1. Estimate your basic energy needs.

Multiply your current weight (in pounds) by 10 if you’re a woman or 11 if you’re a man. Or use the formula in table below, which factors in your age in addition to your sex.

For example: Sue is a 45-year-old female who weighs 155 pounds. 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 = 1,441.92 calories

So Sue’s BMR — or the number of calories that her body needs at complete rest to function — is roughly 1,442 calories.

If you figure Sue’s BMR by using the shortcut method, her needs are about 1,550 (155 pounds x 10 = 1,550) — a bit higher than the full calculation, but still in the same ballpark.

How Many Calories Your Body Needs Per Day for Basic Energy Needs
Age Use This Equation to Calculate Your BMR
* Men
18 to 30 [15.3 x weight (in kilograms)] + 679
30 to 60 [11.6 x weight (in kilograms)] + 879
Older than 60 [13.5 x weight (in kilograms)] + 487
* Women
18 to 30 [14.7 x weight (in kilograms)] + 496
30 to 60 [8.7 x weight (in kilograms)] + 829
Older than 60 [10.5 x weight (in kilograms)] + 596
1. Determine your activity factor value.

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

How Active Are You?
Sitting or standing; driving; painting; doing laboratory work;
sewing, ironing, or cooking; playing cards or a musical instrument;
sleeping or lying down; reading; typing
Very light 0.2
Doing garage, electrical, carpentry, or restaurant work;
house-cleaning; caring for children; playing golf; sailing; light
exercise, such as walking, for no more than 2 miles
Light 0.3
Heavy gardening or housework, cycling, playing tennis, skiing,
or dancing; very little sitting
Moderate 0.4
Heavy manual labor such as construction work or digging;
playing sports such as basketball, football, or soccer;
climbing
Heavy 0.5
1. Multiply your basic energy needs by the activity factor value that you determined in Step

Using Sue as an example, she multiplies her BMR of 1,442 by 0.3 because her activity level is light — running around after her kids, taking care of the house, and fitting in a 2-mile morning walk with her neighbors every other day. Sue needs 432.6 calories for her activity level.

1,442 x 0.3 = 432.6 calories

2. Determine the number of calories that you need for digestion and absorption of nutrients.

Eating food actually burns calories. Digesting food and absorbing nutrients uses about 10 percent of your daily energy needs. Add together your BMR and activity calories and then multiply the total by 10 percent.

The calculation for Sue’s calorie needs for digestion and absorption looks like this:

1,442 calories + 432.6 calories = 1874.6 x 10% = 187.5 calories