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How many calories should you eat in a day

March 29, 2023
12 minutes
Healthy Eating
Nutritional guidelines

A comprehensive guide to calorie count calculations

For people starting a health journey, counting calories is a common place to begin. Calorie counting can be an effective way to reach fitness and weight loss goals, and it can also help you take better control over your health. Yet many aren’t fully aware of what calories are and how they should calculate them. 

If you’ve been asking, “How many calories should I eat in a day?” then this guide is for you.

Calories are the units of energy that come from the foods and beverages you eat and drink. The body uses calories to perform all of its functions, from moving and exercising to circulating the blood and digesting food. If you consume more calories than you use, the extra calories get converted into fat, which the body can use later if it has a calorie deficit.

Controlling caloric intake, and consuming fewer calories than you burn through exercise and daily activity, can be an effective weight control method. To do this, you must understand the calorie count in your favorite foods and how many calories you need in a day.

Some foods, like fatty meats, high carbohydrate foods, or fried foods, have high calorie counts. For example, a hamburger patty with no toppings or bun has around 200 calories. Add all of the toppings and a bun, and you can easily have 1,000 calories in just the burger. 

Other foods, usually fruits and vegetables, have lower calorie counts. One cup of fresh cucumber slices has just 16 calories, and one cup of strawberries has 49 calories.

For many people, calorie counting can be a good, healthy way to start taking back their health. Yet many myths circulate about how many calories someone needs to eat a day and how to calculate them. These myths can make achieving your health goals more challenging. Also, there are potential drawbacks to calorie counting. Before you start monitoring your calorie intake or focusing on weight loss or gain, always talk to your doctor. A thorough health assessment from a qualified healthcare practitioner is vital to ensuring you’re doing what’s best for your health with all of your health conditions taken into consideration. 

Here’s the truth about caloric intake and how to effectively calculate the right number of calories for your body, activity level, and age. Keep in mind, each individual is unique, and some health conditions, medications, and other factors not mentioned here can impact your caloric needs. Before you start a journey toward health by changing your diet, always talk to your doctor to ensure you account for all of these potential factors.

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Calorie counting depends on multiple factors

Counting calories isn’t a one-size-fits-all process. Many factors impact how many calories you need to eat, including health conditions, age, biological sex, activity level, and your fitness goals. Your body shape also impacts your caloric needs. To accurately calculate your caloric needs, you’ll need to consider all of these.

Health conditions

Certain health conditions can impact the metabolism, which increases or decreases caloric need. These include:

  • Metabolic disorders, like thyroid disorders or Cushing’s syndrome
  • Diabetes
  • Wilson disease
  • Mitochondrial diseases
  • Hormonal disorders

If you have one of these or a different chronic health condition, talk to your doctor before working on caloric intake. 


Body mass and muscle density change as you age, which changes caloric intake. 

A child needs a different level of calories than an adult. Most healthy children don’t need to count calories, but rather should learn to eat when hungry and choose healthy, nutrient-rich foods. Children should also focus on regular physical activity as a way to encourage a healthy body mass. 

Counting calories too early can lead to body image and eating issues, unless a parent is working with a doctor for this. That said, Healthline recommends the following ranges for children and teenagers:

  • 5-8 years old: 1,200 to 2,000 calories a day
  • 9-13 years old: 1,600 to 2,600 calories a day
  • 14-18 years old: 1,800 to 3,200 calories a day

Adults also have different calorie needs as they age. Young adults need more calories than older adults, often due to the higher activity levels for these age groups as well as the overall changes your body’s going through as you get older. Here is a general breakdown of calorie ranges for adults:

  • 19-30 years old: 2,000 to 3,000 calories a day
  • 31-59 years old: 1,800 to 3,000 calories a day
  • 60 years old and older: 1,600 to 2,600 calories a day

These ranges are based on a person’s basal metabolic rate, or BMR. This number is the number of calories a person uses for basic daily life functions, such as breathing, digesting or circulating the blood. For all age groups, the range is quite large. That’s because there are other factors at play that impact your ideal calorie count. 

In addition, you should consider average calories per day, as some days you’ll be hungrier or more active than others. Keep your average within your recommended range to keep yourself at a healthy weight.

Biological sex

A person’s biological sex also impacts caloric needs. The University of Pittsburgh Medical Center indicates women have a lower BMR than men. In other words, a woman’s daily bodily functions, including breathing and digesting food, take fewer calories than the daily bodily functions of a man. Thus, someone who was born female needs fewer calories than someone who was born male, even if they have similar daily activity levels.

On the recommended calorie intake ranges listed above, women tend to need calorie counts towards the lower end, while men tend to need the counts at the higher end. Recent recommendations from the USDA recommend 1,600 to 2,400 calories a day for adult women and 2,000 to 3,000 calories a day for adult men, according to USA Today.

Those who identify as a gender other than their biological sex should talk to their doctor about how hormone therapy or gender-affirmation surgery affects their caloric needs, as this is an area that’s still under research. Unless the BMR changes, the recommendations typically still remain with the person’s biological sex at birth.

Activity level

The more active you are, the more calories you need to fuel those activities. An elite athlete needs more calories a day than the average person, and may even need numbers higher than the recommended average calories per day on heavy workout days. Conversely, if you live a sedentary lifestyle or have a desk job with little exercise, you may need fewer calories. Your body isn’t working as hard, and thus it doesn’t need as much fuel.

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Health goals

Your health goals also impact the amount of calories you need. If you want to gain weight, adding more calories that are high in nutritional value may help.

If you want to lose weight, consuming fewer calories than you burn through your regular activities may help you reach that goal. Cutting calories too low can create health issues, though. You won’t get all of your nutrients if you cut calories below your recommended range, and you may put your body into starvation mode, which triggers fat-storage hormones.

Additional factors

A few additional factors that impact your caloric intake needs include:

  • Physical health conditions – If you’re fighting illness, you may need to change your caloric intake to accommodate. Thyroid and other hormone imbalances can also affect your metabolism, changing your caloric intake needs. Similarly, people who are pregnant need more calories than those who are not.
  • Medications – Some medications can speed up or slow down your metabolism, and you may need to adjust your caloric intake accordingly.
  • Body size – Even if you’re trying to lose weight, your body size impacts how many calories you need. Someone who weighs 200 pounds needs more calories for daily functions than someone who weighs 150 pounds. This also means your caloric intake needs will change as you achieve fitness goals and lose weight. Thus, learning to calculate calories by weight is important.

These factors may require the input of your doctor or nutritionist, but it’s worth noting that there are these additional factors at play when determining how many calories you need to eat.

The bottom line – calorie counts are personal

With all of the factors that impact your daily caloric need, learning how to calculate caloric intake is a highly personal process. To help you discover how many calories you need, the right tools can help.

How to calculate caloric intake

One popular method to calculate caloric intake is the Harris-Benedict Equation, which can help you estimate your daily caloric needs. It gives you a person’s BMR, or the number of calories they burn at rest. The BMR is a good starting point for calculating daily caloric needs. Here is a breakdown of the equation:

  • Men: BMR  = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) - (5.677 x age in years)
  • Women: BMR = 447.593 + (9.247 X weight in kg) + (3.098 x height in cm) - (4.330 x age in years)

BMR does not account for activity levels. If you’re regularly active, you’ll need to multiply the BMR by an activity factor:

  • Sedentary: BMR x 1.2
  • Lightly Active: BMR x 1.375
  • Moderately Active: BMR x 1.55
  • Very Active: BMR x 1.725
  • Extra Active, such as a physically demanding job: BMR x 1.9

Use a calculator to help

Calorie counting calculators are tools that let you calculate calorie intake by weight, body size, activity level, and age, so you can have a target daily calorie goal to reach. This takes the guesswork out of the process and gives you the tools to consider all of the factors impacting your calorie needs.

Evidation partners with over 20 health and fitness apps, and many offer calorie calculators. Consider these:

  • MyFitnessPal
  • Samsung Health
  • Apple Health

Once you know your daily calorie range, you can use Evidation to track your food and earn points and rewards, while also calculating your caloric intake for the day. You can also connect your fitness tracker to Evidation to get a better picture of how active or sedentary you are, which in turn will help you use a calorie calculator more effectively.

The potential drawbacks of calorie counting

Calorie counting can be a helpful tool as you work toward your weight loss or weight gain goals. However, it can have potential drawbacks. 

First, calculating calories can be time-consuming. Doing it manually leaves room for human error, and using a calculator requires you to log every bite you take. Some people may find this takes too much time if they live a busy lifestyle.

Second, calorie counting may not be appropriate for everyone. Healthline warns that people who have a history of eating disorders could find their symptoms worsening if they focus on calorie counting. One 2018 study indicated that counting calories combined with frequent self-weighing increased the severity of eating disorders among college-age participants. If calorie counting causes you to feel guilt, shame, or anxiety, then this may not be the right tool for you to reach your health goals.

Choosing smart calories

Counting calories is an important part of taking charge of your health, but you also need to make sure you’re getting enough nutrients in the calories you consume. Consuming all of your calories through sugary drinks or foods could leave you void of vital nutrients, and you’ll struggle to achieve wellness. These tips will help you choose the right foods to get your calorie count for the day.

Avoid cutting calories too drastically

First, make sure you’re not cutting calories too drastically. Most people need at least 1,600 calories a day, and you never want to go lower than 1,200 calories a day without a doctor's oversight. Doing so puts you at risk for nutrient deficits and metabolism problems, according to US News. You’ll also trigger stress hormones, which can cause weight problems. Stay within the recommended ranges for your age, sex, body type, and overall activity level, but aim for the lower end of the range.

Avoid empty calories 

Empty calories are calories that add no nutrients to your body. Specifically, the University of Michigan defines empty calories that come from unhealthy fats or added sugars in foods, as these ingredients do not have nutritional value. 

Empty calories are usually found in processed foods with high sugar and saturated fat content. Examples include:

  • Ice cream
  • Processed meats, like sausages or hot dogs
  • Sodas, non-juice fruit drinks, and many sports drinks
  • Cakes, donuts, and similar baked goods
  • Fried foods, like french fries and chips
  • Candy

These foods have little nutritional value because they lack vitamins, minerals, and fiber. They’re great for occasional snacks and treats, but they aren’t a great choice for your daily nutrition. Sugary beverages are a huge source of empty calories because they don’t even stop hunger.

Choose nutrient-rich foods

Instead of foods with empty calories, choose foods that are high in vitamins, minerals, and fiber but low in calories. These are known as nutrient-rich foods. Most fruits and vegetables fall into this category. The American Heart Association indicates nutrient-rich foods are those that have high vitamin, mineral, and other nutrient content, without added sugars, saturated fats, and sodium. These foods often contain more fiber, too, which helps with feelings of fullness. Specifically, fruits, whole-grains, and vegetables are nutrient rich. Lean proteins, most seafood, and low-fat dairy foods also fall into this category, as do nuts and legumes.

Sometimes, making this switch means choosing healthier options for the same food. For example, if you need a piece of bread, you could choose a whole-grain slice or a non whole-grain. If you read the packaging, you may find that the whole-grain version has more fiber, higher vitamin content, and even more protein than the white bread, but with around the same number of calories per slice. The best choice for nutrient density would be the whole-grain option. 

Applesauce also shows the contrast between nutrient-rich foods and empty calorie foods. Applesauce comes from fruit and thus has a high amount of vitamin E content. However, sweetened applesauce adds sugars, which add empty calories. You could choose unsweetened applesauce or applesauce blended with another fruit instead, and avoid taking in the empty calories from the unnecessary sugar.

Even if your goal is to gain weight, not lose it, the nutrients in the foods you eat are important for your health. Thus, you still need to avoid empty calories. Instead, choose healthy carbohydrates and fats to add the calories you need for weight gain.

Choose healthy carbs

Simple carbohydrates can also be a source of empty calories. These foods digest quickly and cause blood sugar spikes, according to the American Heart Association. Both of these issues may derail your fitness and health goals. This doesn’t mean all carbs are bad, though. You need complex carbs to provide energy and keep you feeling full for a long time. Complex carbs are carbs paired with high levels of fiber. Choose vegetables, beans, legumes, and whole grains to give you the complex carbs you need.

Opt for lean proteins

Protein is also important when building a healthy diet. It builds muscles, which you need if you’re adding exercise to your routine. More muscle density also could raise your BMR. The American Heart Association recommends between 46 and 56 grams of protein a day, which is 10 to 35% of your daily caloric intake. You need protein, but the proteins you choose are important when considering your health goals and calorie needs. 

To optimize your calorie counts, consider lean proteins, like poultry and lean cuts of red meat. These will provide the protein you need without unnecessary calories from fat. 

Look at eating plans

Another option to help you get enough nutrition while staying within a calorie range is to choose an eating plan, such as the Mediterranean diet or the paleo diet. If these diets work with your eating and health goals, they can give you good boundaries to stay within a calorie range, avoid empty calories, and focus on complex carbs with lean proteins.

Take charge of your health

If you’re ready to take charge of your health, download the Evidation app. Start earning rewards while tracking the steps you're taking to improve your health.

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