Whether its emergency food to sustain you and your family during a disaster, or freeze-dried food to lighten the load while backpacking, it’s critical to know how many calories you need under various conditions. Fortunately, with the right information, it’s easy to figure out how much you need.

Begin by calculating your “BMR” or Basal Metabolic Rate:

**For Women**: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)

**For Men**: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.8 x age in years)

If you like, you can simply use this online food calculator.

Once you have your BMR, use what’s called the Harris Benedict Equation to apply an “activity factor” to determine your Calories Required To Keep You From Hitting the Wall or “CRTKYFHW” (okay, we made that acronym up and were hoping it would spell something cool). Multiply your BMR by the appropriate activity factor, as follows:

- If you are sedentary (little or no exercise): Calorie-Calculation = BMR x 1.2
- If you are lightly active (light exercise/sports 1-3 days/week): Calorie-Calculation = BMR x 1.375
- If you are moderately active (moderate exercise/sports 3-5 days/week): Calorie-Calculation = BMR x 1.55
- If you are very active (hard exercise/sports 6-7 days a week): Calorie-Calculation = BMR x 1.725
- If you are extra active (very hard exercise/sports & physical job or 2x training): Calorie-Calculation = BMR x 1.9

With your calories-required calculation (CRTKYFHW) number in mind, check out the nutritional information on the back of your dehydrated food packs.

If you’re a vegetarian, the biggest concern is getting enough protein, especially when you’re using emergency food or survival food. Here’s how to figure out how much you protein need:

As a general rule, between 10 percent and 15 percent of your total calories should come from protein. A gram of protein has 4 calories. To calculate your needed protein, take the BMR number you calculated above and multiply it by .10 then divide by 4.

BMR x .10 / 4 = grams of protein per day

Generally, women need about 40 grams and men need about 50 grams of protein per day.