The Calorie Calculator can be used to estimate the number of calories a person needs to consume each day. This calculator can also provide some simple guidelines for gaining or losing weight.

What are calories?

Calories are the energy in food. Your body has a constant energy demand and uses the calories from food to keep working. Energy from calories fuels your every action, from fidgeting to marathon running.

Carbohydrates, fats, and proteins are the types of nutrients that have calories and are the main energy sources for your body. No matter where they come from, the calories you eat are either converted to physical energy or stored within your body as fat.

These stored calories will stay in your body as fat unless you use them up. You can do this by cutting how many calories you take in so that your body must draw on reserves for energy. Or you can add more physical activity so that you burn more calories.

Tipping the scale

Your weight is a balancing act, but the equation is simple. If you eat more calories than you burn, you gain weight. And if you eat fewer calories and burn more calories through physical activity, you lose weight.

In the past, research found that about 3,500 calories of energy equaled about 1 pound (0.45 kilogram) of fat. So researchers thought burning or cutting 500 calories a day led to losing 1 pound a week. But this isn’t true for everyone.

In general, if you cut about 500 calories a day from your usual diet, you may lose about ½ to 1 pound a week. But this can vary depending on your body, how much weight you want to lose, your gender, and activity level.

It sounds simple. But it’s more difficult because when you lose weight, you usually lose a mix of fat, lean tissue, and water. Also, because of changes in the body resulting from weight loss, you may need to cut calories further to keep losing weight.

Cutting calories

Cutting calories requires change, but it doesn’t have to be hard. These changes can have a big impact on the number of calories you take in:

• Skipping high-calorie, low-nutrition items
• Swapping high-calorie foods for lower-calorie choices
• Cutting portion sizes

Steps to Use Calorie Counting for Weight Loss

Calorie counting is one of the most popular and effective ways to lose weight. In simple terms, weight loss happens when you consume fewer calories than your body burns. By tracking your calorie intake and maintaining a calorie deficit, you can gradually reduce body weight in a controlled manner.

Although the idea sounds simple, calorie counting involves understanding your body’s energy needs, setting realistic goals, and staying consistent over time.

1. Calculate Your Daily Calorie Needs.

The first step is to estimate how many calories your body requires each day. This is usually based on your Basal Metabolic Rate (BMR), which is the number of calories your body needs to perform basic functions while at rest.

Your total daily calorie needs also depend on your activity level. Keep in mind that these calculations are estimates, not exact numbers.

2. Set a Realistic Weight Loss Goal.

A common rule is that losing around 1 pound (0.45 kg) of body weight requires a calorie deficit of approximately 3,500 calories.

This means reducing your intake by around 500 calories per day may help you lose about 1 pound per week.

However, results vary from person to person. It is generally recommended not to lose more than 2 pounds per week, as rapid weight loss may have negative health effects.

3. Track Your Food Intake.

Use a calorie-tracking app, food journal, spreadsheet, or notebook to record what you eat each day.

Many apps contain calorie information for common foods, packaged products, and restaurant meals, making tracking easier.

Over time, you will become better at estimating portion sizes and calorie content.

4. Monitor Your Progress.

Track your weight regularly, but avoid focusing on daily fluctuations. Body weight can change from water retention, meal timing, or sodium intake.

It is better to compare weekly trends rather than daily numbers.

For consistency, weigh yourself under similar conditions, such as in the morning before breakfast.

5. Adjust When Needed.

If progress slows down, you may need to slightly reduce calories, improve food quality, or increase physical activity.

Weight loss is rarely perfectly linear, so patience and consistency are important.

How to Use the Calorie Calculator

All need to do is enter a few basic pieces of information about yourself, including:

• Age: Needs can vary by age, especially as muscle mass naturally declines over time.
• Sex: Though it’s just one consideration, men and women tend to have different calorie needs.
• Height and Weight: Your height and weight help determine your calorie needs.
• Activity Level: Whether you’re sedentary or highly active, your activity level plays a big role in the calculation.
• Fitness Goals: Whether you’re aiming to lose weight, build muscle, or maintain your current health, the calculator adjusts your recommendations accordingly.

How Calorie Needs Are Calculated?

Knowing how many calories you need can help guide your food and activity choices to reach your goals. This is the whole idea behind the CICO diet, which stands for Calories In Calories Out. 

The logic behind the CICO diet is that once you know your caloric needs, you can add, subtract, or meet them to gain, lose, or maintain weight. 

Keep reading for a step-by-step guide to calculating your caloric needs using the Mifflin-St Jeor equation. Plus, you’ll learn how to work with that number once you know it.

Step 1: Calculate Your Basal Metabolic Rate (BMR)

It all starts with the basal metabolic rate (BMR). That’s the number of calories your body burns just to stay alive. Even if you stayed in bed all day, your body would still require energy (aka calories) to breathe, pump blood, produce cells and hormones, and so on.

One of the most reliable ways to calculate BMR is by using the Mifflin-St Jeor equation, which factors in your weight, height, age, and gender.

By plugging your own numbers into this formula, you can get a personalized estimate of how many calories your body burns at rest. I say “estimate” because while this is one of the most accurate ways to calculate your BMR, it’s not a perfect science. (More on this later.) 

Let’s take an example and calculate this together. For instance, if you’re a 35-year-old woman who’s 5’4’’ and weighs 165 pounds, you’d first need to calculate your height and weight in centimeters and kilograms. 

• Height in centimeters = height in inches x 2.54 or 64 x 2.54 = 162.56
• Weight in kilograms = weight in pounds ÷ 2.2 or 165 ÷ 2.2 = 75

Now, let’s plug these numbers into the BMR equation.

• BMR = (10 × 75) + (6.25 × 162.56) – (5 × 35) – 161  
• BMR = 750 + 1016 – 175 – 161  
• BMR ≈ 1,430 calories/day

This means your body requires about 1,430 calories each day just to maintain essential functions. However, since you don’t spend all day lying down, you need to adjust your energy needs based on how active you are. (If you’d rather skip the math, you can easily calculate your BMR here.)

Step 2: Adjust BMR Based on Your Activity Level

Now that you know your BMR, you can factor in your activity level to get a more accurate picture of how many calories you really need each day. That’s your total daily energy expenditure (TDEE). TDEE considers your daily movement and adjusts your caloric needs accordingly. To estimate your TDEE, you can use the following activity level multipliers:

Sedentary (little to no exercise)

Use this activity level multiplier if you get minimal activity or movement throughout the day–say, because you drive to work and have a desk job. 

Activity multiplier: BMR × 1.2

Lightly active (exercise 1-3 days per week)

This is when you perform some activity–such as going for a walk–up to three days a week. 

Activity multiplier: BMR × 1.375

Moderately active (exercise 3-5 days per week)

Let’s say you walk a lot in your day-to-day life and exercise most days; you’d be considered moderately active.

Activity multiplier: BMR × 1.55

Very active (exercise 6-7 days per week)

If you’re engaging in any purposeful exercise–like hopping on the elliptical –most days, or you have a physical job, you’d be considered very active.

Activity multiplier: BMR × 1.725

Super active (hard exercise or physical job)

You’d be considered super active if you pushed yourself hard when you work out–say in spin class–or if you have an intensely physical job.

Activity multiplier: BMR × 1.9

Getting back to our example, if you exercise four times per week, your activity multiplier would be BMR × 1.55. Your BMR was 1,430 calories, so the equation looks like this.

TDEE = 1,430  × 1.55 = 2,216.50 calories/day

This means that for you to maintain your current weight, you’d need around 2,215 calories per day. Now, we’ll adjust this number based on your goals. 

Step 3: Set Your Goal: Weight Loss, Maintenance, or Gain

Here’s where you’ll learn how to calculate your caloric needs depending on your personal goal.

For weight loss:

The logic behind the CICO diet is that a pound is roughly equivalent to 3,500 calories. Therefore, to lose weight, you’d subtract 250 to 500 calories from your TDEE.  

Using our example TDEE of 2,215, you can cut your intake by 500 calories, aiming for a daily intake of around 1,715 calories. This should lead to a gradual, sustainable weight loss of about 1 pound per week. 

Remember that gradual changes are helpful because they don’t feel overwhelming. Also, keep in mind again that while calorie counting is a helpful tool for weight loss, it isn’t a precise science. You may lose more or less weight than predicted after calculating your personal caloric needs for weight loss.

For weight gain:

If you’re trying to gain muscle or increase your weight, you’ll need to consume more calories than your TDEE. Your caloric needs for weight gain can increase by about 500 calories per day, bringing your total to around 2,715 calories.

A calorie-counting tool will come in handy as you focus on adding calories for weight gain. We can also make it easier to ensure you’re adding calories from nutritious sources.

For maintenance:

For weight maintenance, aim to match your calorie intake to your TDEE. In our example, that would mean consuming about 2,215 calories per day.

Whatever your goal, making small, gradual adjustments is the best way to ensure long-term success. Extreme caloric deficits or surpluses can be difficult to sustain and may negatively impact your health. A calorie-counting app can help you follow the CICO diet for weight gain, loss, or maintenance.