Reducing the number of calories you eat per day can be an effective weight loss method (1).
However, figuring out exactly how many calories you should eat can be tricky, as it depends on a variety of factors, including your age, sex, size, and activity level.
Below is a simple scientific calorie calculator, along with 5 evidence-based tips on how to sustainably reduce your calorie intake.
Enter your details in the calculator below to figure out how many calories you should be eating per day to either maintain or lose weight.
The calculator is based on the Mifflin-St Jeor equation and can provide an estimate of your calorie needs. It utilizes population data, as well as other factors, including genetics, medications, and lean body mass, that affect your calorie needs (2, 3).
The number of calories you should eat per day depends on numerous factors, including your age, sex, height, current weight, activity level, and metabolic health, among several others.
When trying to lose weight, its important to create a calorie deficit by consuming fewer calories than you normally do or by exercising more. Some people choose to combine the two, eating a little less while being more physically active (4).
Still, its important to ensure that youre eating enough calories to provide your body with the nutrients it needs, even if youre trying to lose weight.
The most important part of any weight loss plan is sustainability. This is why many experts recommend small calorie reductions to promote sustainable weight loss.
For example, many fad diets recommend restricting your calorie intake to around 1,0001,200 calories per day, which is not enough for most healthy adults.
Cutting your calorie intake too drastically not only causes several serious side effects but also increases your risk of nutritional deficiencies. It likewise results in metabolic changes that make long-term weight maintenance difficult (5, 6).
Heres a closer look at how many calories you should eat, based on recommendations from the U.S. Department of Agricultures (USDAs) 20202025 Dietary Guidelines for Americans (7).
Calorie needs for women can depend on their age, size, and activity level.
Most women between the ages of 1930 require 2,0002,400 calories per day to maintain their weight.
Women between the ages of 3159 have slightly lower energy needs. Generally, women in this age group should consume 1,8002,200 calories per day to maintain their body weight.
Women over age 60 generally require fewer calories and typically need to take in around 1,6002,000 calories per day to maintain their weight (7).
Keep in mind that the exact number of calories that you need may fall on the high or low end of this range or even exceed it depending on how active you are, plus your height, weight, and health status.
Additionally, these estimates dont apply to those who are pregnant or breastfeeding, as theyll need significantly more calories.
As is the case for women, calorie needs for men may range based on several factors.
The most recent Dietary Guidelines for Americans estimates that men between the ages of 1930 should consume 2,4003,000 calories per day to maintain their weight.
Energy needs decrease as you get older. In fact, men between the ages of 3159 need about 2,2003,000 calories per day to maintain their weight, while men over 60 generally require 2,0002,600 calories (7).
Men who are very active or have certain health conditions may require more calories. The number you need within these ranges also varies based on your height and weight.
Children have widely varying calorie needs based on their age, size, and activity level.
Energy needs for children and teens vary based on their sex and age. A 3-year-old child might need only 1,200 calories, but a teenager can require closer to 3,000 calories (7).
However, keep in mind that theres typically no need to count calories for growing children and teens.
In fact, cutting a childs calorie intake may increase their risk of nutritional deficiencies, slow growth, and foster an unhealthy relationship with food or an eating disorder (8).
Instead of counting calories, its best to encourage healthy, nutrient-dense foods, cook more meals and snacks at home, and promote regular physical activity for kids and teens.
The amount of calories that your body needs can vary depending on your age, sex, activity level, and body size.
Simply put, a calorie is a unit that measures energy. Calories are usually used to measure the energy content of foods and beverages.
To lose weight, you need to eat fewer calories than your body burns each day. Conversely, to gain weight, you need to consume more calories than you expend (1).
Keep in mind that while the calories in, calories out concept of weight loss may seem simple, many factors contribute to weight loss or the inability to lose weight, including medical diagnoses, hormonal changes, genetics, and age (9).
Developing a healthy diet and lifestyle plan that will help you lose weight and keep it off in the long term requires much more than determining your current calorie needs and eating fewer calories in response (9).
Calories are units that measure the energy content of foods and beverages. While many factors can influence weight loss, you generally need to eat fewer calories than you burn to lose weight.
Although decreasing the number of calories you consume can be effective for weight loss, cutting calories without considering which foods you eat isnt a sustainable way to lose weight.
For example, choosing more nutrient-dense foods think whole grains, nuts, vegetables, and fruits benefits your health more than opting for nutrient-poor ones like soda, donuts, and candy.
For this reason, its highly recommended to make a few other changes to your diet and lifestyle that can help you maintain a calorie deficit in the long run without feeling hungry or deprived.
Here are 5 simple strategies that may help you lose weight.
When it comes to losing weight, protein is incredibly important.
Studies show that increasing your intake of protein may help keep you full and curb your appetite (10, 11).
Protein may also help fight cravings. According to some research, high protein snacks help enhance feelings of fullness while decreasing hunger and appetite (12).
In addition to promoting weight loss, some research suggests that maintaining a high protein diet may prevent or reduce weight regain and help maintain muscle mass (13, 14).
Therefore, if you want to achieve long-lasting, sustainable weight loss, consider increasing your protein intake by eating more eggs, meat, poultry, tofu, nuts, seeds, or legumes.
Another relatively easy change you can make is to limit your intake of sugar-sweetened beverages, including sodas, fruit juices, chocolate milk, and other drinks with added sugar.
Your brain doesnt register liquid calories the same way it does solid calories, so they affect your feelings of hunger and fullness less significantly (15).
Additionally, studies associate drinking sugary beverages with an increased risk of obesity (16, 17).
The harmful effects of sugar also go far beyond weight gain. In fact, added sugar may contribute to other health issues, including heart disease, liver problems, and type 2 diabetes (17).
One simple thing you can do for your health is to drink more water.
Adequate hydration is associated with improved brain health and weight management, as well as a reduced kidney stone risk (18).
Whats more, drinking water immediately before meals may reduce hunger and help you eat fewer calories (19, 20).
When combined with a healthy diet, drinking more water especially before meals appears to be helpful if you need to lose weight. Try other unsweetened beverages like coffee, tea, and sparkling water to meet your hydration needs.
Calorie restriction, especially significant calorie restriction, may slow your metabolic rate and increase appetite. Plus, cutting calories too severely may lead to muscle loss, which can harm your overall health and lower your metabolic rate.
Resistance-training activities like weightlifting have been shown to limit muscle loss, which may help minimize metabolic changes during long-term calorie restriction (21).
If you cant get to a gym, consider doing bodyweight exercises, such as pushups, squats, and situps, at home.
Cardio exercises, such as walking, swimming, or jogging, are also important both for increasing weight loss and supporting overall health (22).
Additionally, exercise has a variety of other benefits that go beyond weight loss, such as increased longevity, enhanced energy levels, improved mental health, and a decreased risk of chronic disease (23, 24, 25, 26).
The term refined carbs refers to grains that have lost their bran and germ, including white bread, pasta, crackers, and white rice. It also includes sugar and other sweeteners.
Refined grains typically lack fiber, which supports weight loss by decreasing your appetite and increasing feelings of fullness (27).
Eating fewer carbs, including fewer refined carbs, may also promote weight loss by altering levels of specific hormones that regulate your appetite, such as peptide YY (28).
While a low carb or ketogenic diet definitely isnt right for everyone, replacing refined carbs with a variety of nutrient-dense, fiber-rich carb sources such as whole grains, root vegetables, nuts, seeds, and legumes may be beneficial.
Its also best to avoid ultra-processed foods, which include fast food, packaged snacks, candies, and sugary beverages. These items not only pack refined carbs but also preservatives, sugars, unhealthy fats, salt, and other ingredients you should limit in your diet.
Eating more protein, exercising, staying hydrated, and limiting your intake of refined carbs and sugary beverages are a few simple ways to decrease your daily calorie intake.
In addition to cutting calories, there are several steps you can take to lose weight in a sustainable, long-lasting manner:
In addition to decreasing your daily calorie intake, the tips outlined above may support long-term weight loss.
Although counting calories can be an effective strategy for weight loss, its important to remember that there are many other factors to consider when choosing what and how to eat.
Instead of focusing solely on calories, its best to follow a balanced diet thats rich in a variety of nutritious, whole foods. This can ensure that youre getting the vitamins, minerals, and nutrients that your body needs to support weight management and overall health.
If you do decide to cut calories, be careful not to decrease your intake too much, as doing so may cause several serious side effects, including increased hunger, dizziness, fatigue, headaches, and nausea (4).
Eating too few calories may also slow your metabolism, making it harder to maintain weight loss in the long term (5).
Losing weight sustainably also takes time. You should focus on small, gradual changes rather than rapid weight loss strategies.
Finally, calorie counting isnt an exact science. Some days your body needs more calories, while on other days it needs fewer. Focusing exclusively on numbers and weight may also lead to disordered eating (33).
Cutting calories too much may harm your health and make it harder to maintain weight loss. Instead of focusing only on calories, concentrate on a well-rounded diet thats rich in nutritious, whole foods.
The number of calories that you should eat for breakfast depends on many factors, including your daily needs, personal preferences, health goals, and overall diet.
While many people find that consuming one-third or one-fourth of their total daily calorie intake for their morning meal works for them, others may need to adjust this amount based on their individual needs.
The number of calories you should eat for lunch or dinner varies based on many factors, including your personal preferences.
For example, while some people may enjoy eating a large lunch and smaller dinner, others may decide to distribute their calorie intake more evenly.
Therefore, because everyones needs and preferences are different, its best to find what works for you and stick to it when planning your meals.
The number of calories that you need to lose weight depends on several factors.
To support sustainable weight loss, cut back on ultra-processed items like sugary beverages, ice cream, fast food, and high calorie snack foods. Furthermore, try increasing your physical activity.
A dietitian can help you determine your calorie needs and an appropriate calorie goal to support weight loss.
To gain weight, you need to be in a calorie surplus, meaning that you take in more calories than you burn.
Try eating more high calorie, nutrient-dense foods like nut butters, full fat yogurt, and fatty fish.
Gaining muscle typically requires a calorie surplus, meaning that you should eat more calories than you expend throughout the day.
You may have to increase your calorie needs by a few hundred calories per day. A sports dietitian can help you develop an appropriate plan (34).
The number of calories that you should eat at each meal or to reach a specific weight goal can differ. Therefore, its best to experiment to find what suits your needs.
Many websites and apps can help you track your calorie intake.
You can try using a calorie counter or tracker for at least a few days to see the amount of calories, carbs, protein, fat, fiber, vitamins, and minerals youre eating.
This can be an easy, effective way to identify any gaps in your diet and make modifications to ensure that youre getting the nutrients your body needs.
Working with a registered dietitian (RD) can also help you gain, maintain, or lose weight while ensuring that your nutrient needs are being met.
Tracking your food intake can help you determine how many calories youre eating per day and identify any gaps in your diet.
How many calories you need per day depends on whether you want to maintain, lose, or gain weight, as well as various other factors, such as your sex, age, height, current weight, activity level, and metabolic health.
Although counting the number of calories that you consume may aid weight management, its also important to follow a balanced diet and consider the overall nutritional value of the foods you eat.
Making simple dietary and lifestyle changes, including exercising, drinking plenty of water, and increasing your protein intake, may help you lose weight and improve your health.
More:
How Many Calories Should You Eat? Weight Loss Calculator - Healthline
