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How to Calculate Calories for Greater Weight Loss Success

Reading Time: 6 minutes


Date: 2022-05-05

A study spanning 30 countries found that 45% of people are actively trying to lose weight. Forty-four percent of these individuals added that they were willing to reduce their calorie intake to help them meet their weight loss goals. 

But how important is daily calorie intake for weight loss success? And how many calories do you have to cut to reduce your body fat? Let’s answer these questions and more.

Calorie Intake and Weight Loss 

If the goal is to lose weight, you must create a calorie deficit. This means that you must take in fewer calories than you use. 

Put another way, when your calorie intake is lower than the number of calories you burn, you lose weight. If it’s higher, it results in weight gain. When calorie intake and calorie burn are equal, weight stabilizes. This is the goal at the maintenance stage.

Creating a deficit requires counting calories. If you don’t pay attention to the food you consume, it’s easy to exceed your calorie needs. Even slight overages add up over time. At a minimum, they can stall weight loss efforts. Go way above your calorie needs and gaining weight is inevitable.

How to Calculate Calories for Weight Loss Success

Each person has different calorie needs. They vary based on your sex, current body size, activity level, and more. Take these four steps to determine the calorie count needed for your weight loss success.

Step 1: Calculate Your Base Metabolic Rate

Before you can calculate how many calories are needed for weight loss, you must first calculate your base calorie need. This is the number of calories needed to simply maintain life. It is known as basal metabolic rate or BMR.

BMR takes into account the calories burned during life-sustaining activities such as breathing, food digestion, and blood circulation. Sometimes, BMR is confused with resting metabolic rate (RMR). But RMR is different in that it is the calories burned while the body is at rest. This includes calories used for more than just basic functions.

One way to calculate BMR is with the Harris-Benedict formula. The formula you use is based on your sex:

Men: 66 + (13.7 x weight in kg) + (5 x height in cm) – (6.8 x age)

Women: 655 + (9.6 x weight in kg) + (1.7 x height in cm) – (4.7 x age)

Step 2: Consider your Level of Physical Activity

Next, take your BMR and use it to determine how many calories you use daily based on your activity level. The more physical activity you get regularly, the greater your calorie burn. The greater your calorie burn, the more food you can consume and still lose weight.

This calculation gives you your total daily energy expenditure or TDEE. To calculate your TDEE, take your BMR and multiply it by the number that coincides with your level of physical activity:

ISSA, International Sports Sciences Association, Certified Personal Trainer, ISSAonline, Calculating Calories for Weight Loss

Step 3: Determine Your Goal Daily Calorie Count

The number you get when multiplying your BMR by your activity level is the number of calories needed to sustain a healthy weight. The question is: how different is this intake compared to your current food plan?

The reason this is important is that trying to reduce your calorie intake too quickly can leave you feeling hungry all of the time. It can also cause you to feel as if you have to deprive yourself to hit your weight-related goals. This can set you up for failure.

Instead of trying to drop immediately down to your recommended calorie amount, devise a plan to get there slowly over time. You might eat 100 fewer calories the first week, for instance. This gives your body time to adjust to a lesser food intake without dealing with major calorie cuts. 

The next week, lower your daily food intake by another 100 calories. While this approach may take a bit longer to lose weight, it is also more sustainable. Besides, creating healthy living habits is a process. Going slow makes the process more enjoyable because the change occurs over time versus shocking the body all at once.

Step 4: Create a Menu with This Total Calorie Count

Once you know how many calories you need to support basic bodily functions while also having the energy needed to exercise and lose weight at a healthy rate, you can plan your food menu. Decide what you’ll eat, how much, and when. Sticking to your daily calorie plan can help you achieve a healthy weight.

Calorie counting also helps you modify your plan if needed. The ideal weight loss rate is 1-2 pounds per week. If your weekly fat loss exceeds this rate, you may want to increase your calories consumed so you don’t drop your weight too fast. 

The problem with losing weight too quickly is that it causes your metabolic rate to slow. A slow metabolic rate leads to slower weight loss. This can be frustrating because you’re doing everything right but still not seeing results.

Lose weight too fast and you could also reduce your muscle mass. Greater muscle mass means a tighter physique. Muscle also increases metabolic rate. So, protecting the muscle you have helps boost your energy expenditure.

Using an Online Calorie Calculator

Some online calculators will tell you your TDEE without having to calculate your BMR first. TDEE Calculator is one option. Select your gender, then input your age, weight, height, and activity level. You can also choose between imperial (pounds and inches) and metric (kilograms and centimeters) calculations. also offers a calorie calculator. This website enables you to calculate calories using your choice of BMR formulas. To see your options, go into the settings. You can choose between the Harris-Benedict, Mifflin St Jeor, and Katch-McArdle equations. 

It should be noted that all three of these formulas provide estimates as to what daily calorie intake should be. So, you might have to modify your daily calorie range based on how your food intake impacts your weight. If the scale is going up instead of down, lower your calorie range. The number provided by the calculator is just a starting point.

Calculating Caloric Needs for Weight Maintenance

Maybe you’re more interested in maintaining your current body weight than in achieving weight loss. Or perhaps you’ve used the above steps and have hit your weight goal. The next step is to determine how many calories you need to maintain your weight. 

To stop weight loss, start to add food to your diet to increase your calorie count. Try adding 100 calories per day and see what happens with your weight. Keep doing this every week until your weight starts to stabilize. Once your weight holds steady, you’ll know what your maintenance calories should be.

Two Ways to Create a Calorie Deficit

We’ve talked a lot about decreasing food intake to help create a calorie deficit. But this isn’t your only option. You can also increase the amount of exercise you get. This forces the body to use more energy, which also results in a deficit.

You don’t have to go all out with your exercise either. If you’re sedentary now, aim for a few light activity sessions per week. If you’re lightly active, work your way up to being moderately active. Each increase in activity means that the body burns more calories to support the needed energy increase.

The benefit of creating a deficit with exercise is that you don’t have to limit your food intake as drastically. Instead, you use your activity to tilt the equation in your favor. 

Choosing High-Quality Calorie Sources

When your goal is weight loss, it’s not just about cutting your calories. You also want to choose foods that offer the most nutritional calorie content.

Fill your plate with lean proteins, complex carbs, fruits, and vegetables. Keep foods high in saturated fat and trans fat to a minimum. This helps support good health while working toward your weight loss goals.

Also, focus more on natural foods than foods that are processed. If you buy anything in a box or can, read the nutrition facts. Pay attention to what you put in your body. The more you meet its nutritional needs, the better it functions. The better it functions, the more effective it becomes at losing weight.

Help Clients Achieve Their Body Weight Goals

Offering clients a personalized eating plan can help them better meet their weight loss goals. Typically, this is outside a personal trainer’s scope of practice. But it’s well within the bounds of a certified nutritionist. 

ISSA’s Nutritionist Certification course provides the ability to create customized menus that take into account your client’s daily calorie needs. Whether their goal is weight loss, they’re trying to maintain their current weight, or are interested in weight gain, you can help get them there by prescribing the right calorie count for their body and physical activity level.

Featured Course


By becoming an ISSA Nutritionist, you'll learn the foundations of how food fuels the body, plus step by step methods for implementing a healthy eating plan into clients' lifestyles.


45% of people globally are currently trying to lose weight. Ipsos. (2021). Retrieved 14 April 2022, from

TDEE Calculator: Learn Your Total Daily Energy Expenditure. (2015). Retrieved 14 April 2022, from

Calorie Calculator. Retrieved 14 April 2022, from

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