How Many Calories Should You Eat in a Day?

A calorie is a measure of energy, often used to express the nutritional value of foods. The energy that food provides is actually measured in kilocalories or kcals, which is the amount of energy needed to raise 1 kilogram of water by 1-degree celsius.

Your body requires a steady supply of calories in order to perform vital functions and maintain healthy energy levels. Your calorie needs depend on a variety of factors, including body weight, activity levels, age, health, and gender. 

For example, people who have a larger body frame will require more calories than people with a smaller body frame. Likewise, people who are physically active need more calories compared to people who are sedentary. 

Men typically need more calories than women due to body size and body composition, but that's not always the case. For example, a woman who’s extremely active may require more calories to maintain her body weight than a sedentary male. 

Other factors, like medical conditions and pregnancy, can influence your energy needs. A person with cancer, for example, may require many more calories per day compared to a person without cancer in order to combat weight loss due to the increased energy demands of the disease.

Another variable is body composition goals. Someone who wants to gain weight needs to take in more calories, while someone who wants to promote weight loss will need to create a calorie deficit by eating less and/or exercising more. 

As you can see, there are a number of variables that influence calorie needs, which makes it difficult to figure out your exact calorie needs without the use of specialized equipment. 

Fortunately, there are general calorie recommendations for adults based on average adult height and weight. 

Female Adults

According to the Dietary Guidelines for Americans, estimated calorie needs for adult women range from 1,600 to 2,400 calories per day. Keep in mind that these ranges are based on the needs of a “reference woman” who is 5 feet 4 inches tall and weighs 126 pounds. 

Females between the ages of 19 and 30 typically need 1,800-2,400 calories per day while women between the ages of 31 and 59 usually require between 1,600-2,200 calories per day. As we age, our calorie needs begin to decline because of reductions in our basal metabolic rate (BMR), which is a term used to describe the calories you burn while you’re at rest.

Smaller females and those who are less active require fewer calories while women with a larger body frame and those who are physically active will need more calories on a daily basis in order to maintain their body weight. 

The following chart breaks down daily calorie needs for moderately active women based on age. According to the Dietary Guidelines for Americans, someone who’s moderately active walks about 1.5 to 3 miles per day at 3 to 4 miles per hour.

Age	Calorie needs per day
19-20	2,200
21-25	2,200
26-30	2,000
31-35	2,000
36-40	2,000
41-45	2,000
46-50	2,000
51-55	1,800
56-60	1,800

Male Adults

Adult men usually require more calories on a daily basis compared to women. The estimated daily calorie needs for men range from 2,000 to 3,000 calories per day. These estimated requirements are based on a “reference man” who is 5 feet 10 inches tall and weighs 154 pounds.

Most males aged 19 to 30 require between 2,400 to 3,000 a day while the calorie needs of males aged 31 to 59 usually lie between 2,200 to 3,000 calories a day.

Like females, smaller and less active males need fewer calories to maintain their weight compared to larger and more physically active men.

Here’s an idea of how many calories moderately active adult men need on a daily basis.

Age	Calorie needs per day
19-20	2,800
21-25	2,800
26-30	2,600
31-35	2,600
36-40	2,600
41-45	2,600
46-50	2,400
51-55	2,400
56-60	2,400

How Many Calories Older Adults Need

As we age, our BMR usually drops due to changes in body composition, including a loss of muscle mass, as well as a gradual decline in physical activity.

Because of this, adults over the age of 60 generally require fewer calories than younger adults.

Female Older Adults

Females over the age of 60 typically require between 1,600 and 2,200 calories per day to maintain their weight.

Older women who are more active will need more calories in order to support body weight maintenance compared to older women who are less active. It’s important to note that although older people usually require fewer calories than younger people, the need for individual nutrients—like protein and vitamin D—increases in order to support healthy aging.

Here are the average calorie needs for moderately active older women.

Age	Calorie needs per day
56-60	1,800
61-65	1,800
66-70	1,800
71 and over	1,800

Male Older Adults

Most men over 60 need between 2,000 and 2,600 calories per day to maintain their weight, which is slightly less than younger men require.

Older men who are more active have higher calorie needs compared to older men who are sedentary. Here’s an estimation of calorie needs for moderately active older men.

Age	Calorie needs per day
56-60	2,400
61-65	2,400
66-70	2,200
71 and over	2,200

How Many Calories Children Need

Children and teens need adequate calories on a daily basis in order to support optimal growth and development. Younger kids need fewer calories compared to adults, while teens often have greater energy requirements compared to adults.   

Estimated energy needs for kids and teens range from 1,000 to 3,200 calories per day based on age and gender. Like adults, male children generally have higher calorie needs than female children.

Children who are highly active, like teen athletes, need more calories on a daily basis compared to moderately active children. A 2022 study found that teen athletes who were training for demanding sports may require up to 5,000 calories per day in order to maintain their body weight.

Female Children

The following chart breaks down the average calorie needs for moderately active female children and adolescents based on age.

Age	Calorie needs per day
2	1,000
3	1,200
4	1,400
5	1,400
6	1,400
7	1,600
8	1,600
9	1,600
10	1,800
11	1,800
12	2,000
13	2,000
14	2,000
15	2,000
16	2,000
17	2,000
18	2,000

Male Children

Older male children generally need more calories than female children. 

The following chart breaks down the average calorie needs for moderately active male children and adolescents based on age.

Age	Calorie needs per day
2	1,000
3	1,400
4	1,400
5	1,400
6	1,600
7	1,600
8	1,600
9	1,800
10	1,800
11	2,000
12	2,200
13	2,200
14	2,400
15	2,600
16	2,800
17	2,800
18	2,800

How Many Calories To Eat During Pregnancy

When you’re pregnant, your body requires more energy to support fetal growth. However, this increase in calorie demands begins in the second trimester, meaning your calorie needs during the first trimester are the same as your pre-pregnancy needs. That said, your need for nutrients, like iron, folate, and choline, increases significantly starting in the first trimester.

This is why it’s recommended that women who are pregnant or trying to get pregnant supplement with a prenatal vitamin to ensure they’re taking in enough vitamins, minerals, and other important nutrients in order to support their health and the health of their baby.

Here’s a general idea of how many extra calories an average woman requires during pregnancy. Keep in mind that women who are underweight generally need more calories and women who are overweight or obese will require fewer calories in order to maintain a healthy body weight throughout pregnancy. 

Stage of Pregnancy	Additional Calories Needed Per Day
First trimester	0
Second trimester	+340
Third trimester	+452

If you’re breastfeeding, you’ll need to bump up your calorie intake, too. In fact, your body needs even more calories during breastfeeding than it does during pregnancy.  

The average woman uses about 500 calories per day to produce milk.

To support energy levels and maintain healthy milk production, breastfeeding women should fuel their body regularly with nutrient-rich meals and snacks and stay hydrated by drinking plenty of water. 

How Many Calories To Eat for Weight Loss

In order to promote weight loss, you’ll need to create an energy deficit, which means taking in fewer calories than you burn on a daily basis.

This can be done by cutting calories or by increasing energy expenditure through physical activity. 

Most weight loss diets recommend a daily calorie intake ranging from 1,000–1,500 calories per day, which is significantly less than most adults require on a daily basis.

Even though low-calorie diets usually result in quick weight loss, extreme calorie restriction results in compensatory changes in your body, like a loss of muscle mass, increased appetite, and a reduction in BMR. This makes it harder to maintain weight loss long term.

This is why many experts, including registered dietitians, often recommend creating smaller calorie deficits in order to minimize these compensatory changes and promote long-term weight loss success.

If you’d like to lose weight, you could use an online calorie estimator to figure out your average daily calorie needs and then subtract around 200 to 300 calories per day in order to promote slow, yet healthy weight loss.

A simpler way to lose excess body fat without counting calories is to reduce your overall calorie intake by sticking to moderate portion sizes, cutting out sugary beverages like soda and sweetened coffee drinks, and reducing your consumption of snack foods and sweets. 

You can also create a calorie deficit by adding in more physical activity. For example, if you’re currently sedentary, try adding in a daily 30-60 minute walk or taking a beginner workout class at your local gym a few times a week. This will create a small calorie deficit that will promote weight loss over time. Pairing exercise with a reduced-calorie diet can promote weight loss and help you maintain your muscle mass, which can help you maintain a healthy BMR.

If you need help creating a weight loss-friendly diet or have questions about your energy needs, consider making an appointment with a registered dietitian. They can help assess your calorie needs and develop a nutrition and exercise plan that works for you and your health goals. 

A Quick Review

Taking in the right number of calories can help you maintain a healthy body weight and support your energy levels. Because calorie needs are influenced by factors like your activity levels, age, and gender, it can be difficult to figure out how many calories you should be eating. 

If you have questions about your calorie needs or are interested in losing or gaining body weight, consider reaching out to a healthcare provider like a registered dietitian.