How Many Calories a Day Are Needed to Survive?

Food is a requirement of life. People can live for a time without food, but there comes a point where the body requires fuel to continue. However, there is not a single number that can be put forth that is the exact amount needed. The FDA recommends 2200, but that is based on an average, and few people are actually average, by definition. 

The factors that determine the needed amount is based on a person’s height, weight, age, activity level, biological sex, and sometimes hereditary elements. Formulas have been made to help people figure out how much they need, but it is important to remember that everyone is different and even the best formula is going to miss factors for some people. 

Calories represent nutrients. They are generally counted from fat, carbohydrates, and protein. Each component is necessary and cutting out any one completely will cause problems with health. 

Fats are a source of energy. Some vitamins require fat to be absorbed and used by the body. Fat also feeds the brain. The best fats are those that occur naturally in plants such as avocadoes, nuts, and seeds. Meat and dairy products are also providers of dietary fats. 

Carbohydrates are another source of energy. Fruits, vegetables, and grains are foods that are mostly carbohydrates. Simple sugars are carbohydrates, too, but these can have harmful effects on the body. It is better to get carbohydrates from the other sources, especially ones like fruit and vegetables that also provide fiber. The fiber helps to offset the carbohydrates because it is indigestible. Fiber helps to keep things moving through the digestive tract. 

Protein is the building block it aids in growth and healing. Protein is found in dairy and meats, nuts, seeds, and legumes. 

Vitamins and minerals are found in many fruits and vegetables. A healthy diet will usually provide most of the nutrients required to thrive, but if one finds it difficult to ingest enough of any certain vitamin or mineral, supplements can be helpful. Natural nutrients from food are definitely better than supplements, however. 

Determining how many calories you need starts with your basic metabolism. This is how many calories burned when resting. Between 60% and 70% of the calories burned in a day fit in this category which includes the vital parts of living like the beating of the heart, the breathing, blinking, and other things that must happen just to live. This resting rate of metabolism tends to be higher in biological men than in women. The formula to determine this rate, which is usually fairly accurate, is known as the Harris-Benedict formula and is calculated as follows: 

  • Male = 66 + (body weight in pounds x 6.3) + (height in inches x 12.9) – (age in years x 6.8)
  • Female = 655 + (body weight in pounds x 4.3) + (height in inches x 4.7) – (age in years x 4.7)

Once the base rate is determined, the next consideration is the quantity of physical activity. This includes everything from walking across the room to purposeful exercise. Different activities expend different amounts of calories, but generally speaking, the more active a person is, the more calories are expended, and the more calories are needed to maintain health.

The other calories used by the body every day are those used for digesting food. Approximately 10% of the calories eaten each day are used for processing the nutrients through the body. 

Adding these three numbers together will provide the total calories needed in a day. However, these are the calories needed to continue as usual, and survival requires somewhat fewer. It is important to remember that survival calories will not allow for thriving but will allow a person to survive through a catastrophe, though likely at a lower energy level and somewhat less strength over time. Surviving on minimal calorie intake is not healthy and will eventually result in organ failure. 

However, in a case in which food is not plentiful, rationing intake can be necessary for a time. Knowing the minimum calorie intake can be helpful. With this in mind, many experts agree that 1,200 calories is the minimum, but can still result in lowered energy levels, which is definitely not optimal in a survival situation. This will vary from person to person, of course. Most women’s base rate tends to be between 1,100-1,500 calories. 

Lower calorie counts (below 500) can allow a person to survive in extreme situations, but this will necessarily be at the expense of health issues, making it unwise to choose if not necessary. 

An important thing to remember is that water – which has no calories – is also extremely important. One can live longer without food than without water. 


Where to Buy
Edible Wild Plants
Foraging & Feasting
Wild Food
Mediterranean Grains and Greens
Emergency Survival Pack


1. Edible Wild Plants

If food becomes scarce at grocery stores, knowing how to find wild food can make a huge difference in survival chances. This book will assist in finding food in these situations. 

2. Foraging and Feasting

This beautifully illustrated hardcover contains botanical information and recipes for using the foraged items.

3. Wild Food

A complete guide to plants to forage in a variety of locations from woods to beaches, this book includes both recipes for meals and medicinal uses. 

4. Mediterranean Grains and Greens

This book of recipes is based on vegetables and whole grains which provide all the nutrients required for healthy living.

5. Emergency Survival Pack

This kit contains enough provisions to last one person six days and can be stored for up to five years. 

Where to Buy
Ready America 70280 Emergency Kit
Datrex 3600 Calorie Emergency Food Bar for Survival Kits
DATREX Emergency Water Pouch for Disaster or Survival, 125 ml Each
Good Calories, Bad Calories
LETSCOM Fitness Tracker HR


6. 2-Person Emergency Kit

This kit, packed in a handy backpack, contains enough emergency food and water for two people for three days, along with emergency blankets, light sticks, and a first-aid kit.

7. Emergency Food Bars

36 bars of emergency food provide 200 calories each and are made from natural ingredients and have a pleasant coconut flavor. 

8. Emergency Water Pouch

Purified water in lightweight pouches have a shelf life of up to five years. Available in 12, 18, or 64 pouch quantities. 

9. Good Calories, Bad Calories

This book discusses the science involved in a proper diet and how to eat to have a healthy lifestyle.

10. Fitness Tracker

This device, worn on the wrist, can assist in determining activity level accurately. It is waterproof, so activity in rain and other water can still be counted properly.