The number of calories you need to eat per day depends on a variety of factors, including your height, current weight, age, gender and activity level. Therefore, there's not one magic number — use a calories calculator or do the math to figure out what you need on a daily basis.
The number of calories you should eat on a daily basis, whether or not you want to lose weight, depends not only on your height, but also your current weight, age, gender and activity level.
Calories Needed to Lose Weight
Losing, maintaining or gaining weight is all a matter of how many calories you eat versus how many calories you burn each day, according to the Cleveland Clinic. If you eat fewer calories than you burn through physical activity, you'll likely lose weight. However, when you eat more calories than you burn, you're likely to gain fat. The number of calories that your body needs, however, differs from person to person.
If you're only interested in a rough estimate of how many calories you need to eat per day, you don't need to take your height into account — just your age, gender and activity level. The more you move during the day, the more calories you need to take in to maintain your weight. For women, the USDA 2015-2020 Dietary Guidelines for Americans recommends:
- Age 19 to 25: 2,000 to 2,400 calories
- Age 26 to 50: 1,800 to 2,400 calories
- Age 31 to 50: 1,800 to 2,200 calories
- Age 51 to 60: 1,600 to 2,000 calories
- Age 61 and up: 1,600 to 2,000 calories
Men typically need more calories than women, but they can still use an estimate based on age and activity level. The Dietary Guidelines recommends:
- Age 19 to 20: 2,600 to 3,000 calories
- Age 21 to 35: 2,400 to 3,000 calories
- Age 36 to 40: 2,400 to 2,800 calories
- Age 41 to 55: 2,200 to 2,800 calories
- Age 56 to 60: 2,200 to 2,600 calories
- Age 61 to 75: 2,000 to 2,600 calories
- Age 76 and up: 2,000 to 2,400 calories
Taking Height Into Account
If you want a more specific number of how many calories you need to eat per day based on your height, you need to do a little math or find an online calories calculator that does the math for you. Your body burns calories, even when you're not moving, just by doing its basic functions such as breathing and circulating blood.
The number of calories this burns is known as your resting metabolic rate, or RMR, according to the American Council on Exercise (ACE). Your resting metabolic rate takes into account your gender, age, current weight and height to determine how many calories your body needs to maintain its weight while at rest.
However, you're probably not at rest all day — therefore, your RMR isn't the final basis for how many calories you need to eat. The total number of calories you burn on a daily basis is known as your total daily energy expenditure, or TDEE, notes ACE. The TDEE takes into account not only your RMR, but also other sources of caloric burn:
- The number of calories you burn eating (the thermogenic effect of food, or TEF)
- The calories you burn by regular movement (non-exercise activity thermogenesis, or NEAT)
- The extra calories you burn after exercising (excess post-exercise oxygen consumption, or EPOC)
- Exercise itself
Calculating Your Calorie Needs
The first step in determining how many calories you need is to use a calories calculator or follow a formula to figure out your RMR. To do this, use the Mifflin-St Jeor Equation, which differs for men and women:
- Male: 9.99 x weight in kilograms + 6.25 x height in centimeters – 4.92 x age + 5
- Female: 9.99 x weight in kilograms + 6.25 x height in centimeters – 4.92 x age – 161
Using this formula, a woman who is 35 years old and weighs 150 pounds (68 kilograms) and is 65 inches (165 centimeters) tall would need to eat approximately 1,377 calories per day. A 40-year-old man who is 200 pounds (90.7 kilograms) and 72 inches (183 centimeters) tall would need 2,252 calories a day.
The final number will provide an estimate of how many calories your body needs per day when at rest. Keep in mind that it's just an estimate; for a specific number, you'll have to visit a professional to determine your RMR via indirect calorimetry, according to the National Academy of Sports Medicine. This measures the number of calories you burn by analyzing the gases you exhale.
Additionally, your resting metabolic rate doesn't take into account the additional ways your body burns calories beyond basic bodily functions. However, instead of trying to figure out your TEF, NEAT, EPOC and exercise calories, you can figure out a solid, useful estimate by multiplying your RMR by an activity level number:
- Sedentary (little exercise, desk job): multiply by 1.2
- Lightly active (light exercise, one to three days a week): multiply by 1.375
- Moderately active (moderate exercise, three to five days a week): multiply by 1.55
- Very active (hard exercise, six to seven days a week): multiply by 1.725
- Extremely active (Hard daily exercise, physical job): multiply by 1.9
Consider the previous example of a 35-year-old woman who needs 1,377 calories a day: she would need 1,652 calories a day if she lived a sedentary lifestyle, but 2,616 calories if she was extremely active. The man who needs 2,252 calories based on his RMR would need 2,702 calories if he's sedentary and 3,490 calories if he does moderate exercise a few times a week.
Caloric Breakdown by Macronutrient
What you eat is just as important as how much you eat when it comes to living a healthy life. All food is broken down into three groups, or macronutrients: carbohydrates, protein and fat. According to The National Academy of Medicine, a typical diet should consist of 45 to 65 percent carbohydrates, 10 to 35 percent protein and 20 to 35 percent fat.
Carbohydrates are your body's primary source of energy. A wide variety of foods contain carbohydrates but, according to ACE, the type you want to focus on for that 45 to 65 percent of your daily diet are the unprocessed or minimally processed varieties, rather than unprocessed carbs or foods with added sugar. Unprocessed and minimally processed carbohydrates are found in fruits and vegetables, whole grains and beans, and they provide vitamins, minerals, fiber and phytonutrients, according to the Harvard T.H. Chan School of Public Health.
Read more: How Many Calories Are in a Gram of Carb?
Protein is found in every cell, tissue and organ in your body and it's necessary to build and maintain your muscle mass. When looking for smart protein choices, go for lean proteins — this includes lean beef such as top sirloin and round steak, lean pork such as pork loin and ham, lean poultry such as boneless skinless chicken breasts and seafood such as fish and shrimp, says PennState Extension. Legumes such as beans, dairy products, certain grains such as quinoa, soy products such as tofu, and nuts and nut butters also contain protein.
Fat has long had a bad reputation, but your body needs that 20 to 35 percent of your daily diet from the macronutrient. Choose products that contain unsaturated fats, says the Academy of Nutrition and Dietetics, rather than saturated or trans fats. Smart choices include foods with omega-3 fatty acids, such as fatty fish, walnuts, flaxseeds and chia seeds, as well as monounsaturated fats such as olive and canola oil, avocado and peanut butter.
How to Decrease Calories
Now that you know how many calories you need to eat for your height, it might be time to figure out how to cut back on calories if you want to lose weight. Because 1 pound of fat equals around 3,500 calories, you need to cut 500 to 1,000 calories a day to lose 1 to 2 pounds per week, according to the Mayo Clinic.
One of the simplest ways to eat fewer calories is to decrease your portion sizes. It can take time to understand and recognize proper portion sizes. For example, 3 ounces of meat — the recommended portion size — is about the size of a deck of cards or a bar of soap, says the American Cancer Society. You can also cut back by putting a portion of snack foods, such as crackers, in a bowl instead of eating mindlessly from the box.
It's easy to overeat when you're enjoying a meal out because most restaurants serve more food than a person needs, says the Centers for Disease Control and Prevention. Stop the chance of overeating before it starts by splitting an entree with a friend or family member or wrapping up half the meal and taking it home to eat another day.
It's also worth looking into healthy food substitutions that can save you calories. For example, eating four egg whites instead of two whole eggs can save you calories at breakfast, while dipping raw vegetables instead of tortilla chips into salsa makes for a lower-calorie snack, says Mississippi State University Extension.
Don't forget that consuming calories is not just about what you eat, but also about what your drink. Water is your best option, particularly for weight loss, as it hydrates you and has zero calories. However, you can make smart substitutions here, too. Switch from a 20-ounce non-diet drink to a bottle of diet soda or water, and you'll save around 227 calories, according to the Centers for Disease Control and Prevention. Going from a medium cafe latte made with whole milk to a small fat-free caffe latte also saves you 140 calories.
- American Council on Exercise: "Resting Metabolic Rate: Best Ways to Measure It — And Raise It, Too"
- National Academy of Sports Medicine: "Resting Metabolic Rate: How to Calculate and Improve Yours"
- American Council on Exercise: "How to Determine the Best Macronutrients for Your Goals"
- The National Academy of Medicine: "Dietary Reference Intakes: Macronutrients"
- Mayo Clinic: "Counting Calories: Get Back to Weight-Loss Basics"
- American Cancer Society: "Controlling Portion Sizes"
- Mississippi State University Extension: "Eat Less and Cut Calories!"
- Harvard T.H. Chan School of Public Health: "Carbohydrates"
- PennState Extension: "Protein and Protein Supplements"
- Academy of Nutrition and Dietetics: "Choose Healthy Fats"
- Cleveland Clinic: "How Many Calories a Day Should I Eat?"
- USDA 2015-2020 Dietary Guidelines for Americans: "Estimated Calorie Needs per Day, by Age, Sex, and Physical Activity Level"
- Centers for Disease Control and Prevention: "Rethink Your Drink"
- Centers for Disease Control and Prevention: "How to Avoid Portion Size Pitfalls to Help Manage Your Weight"