Calculating Calories: It’s Not Rocket Science, We Promise

You need to know how many calories you eat vs. how many you need to determine if you'll lose weight, gain weight, or maintain. Read on to learn why.

Whether you want to lose fat, gain muscle, or maintain a healthy weight, you need to know how many calories your body needs to thrive. Naturally, the generic recommendation of 2,000 calories per day doesn’t work for everyone. Find out how to calculate your maintenance calories to keep your health and fitness goals on track.

Why TDEE Is the Key to Calculating Maintenance Calories

To calculate your maintenance calories, it’s essential to know your TDEE (total daily energy expenditure). This number includes three main components:

  • BMR (basal metabolic rate)
  • NEAT (non-exercise activity thermogenesis)
  • Exercise

Ultimately, your TDEE factors in your size, your age, your body’s basic energy needs, and your typical activity level to determine how many calories you need to do it all.

How to Calculate Your BMR

If you’ve never tried calorie counting before, it’s easy to assume that most of your daily energy burn happens as a result of your workouts and gym sessions. In reality, your BMR accounts for the majority of your daily energy expenditure. Your BMR includes all of the calories that your body burns as it performs basic functions like digestion, breathing, and cardiovascular activity.

To determine your BMR, multiply your weight in pounds by 10, use a BMR calculator, or try one of the following equations, all of which produce similar results:

  • Harris-Benedict Equation: 655.1 + (4.35 x your weight in pounds) + (4.7 x your height in pounds) – (4.7 x your age in years)
  • Mifflin St. Jeor Equation: (10 x your weight in kilograms) + (6.25 × your height in centimeters) – (5 x your age in years) – 161
  • Katch-McArdle Formula: 370 + (21.6 x (((100-body fat) x your weight in kilograms) / 100)

How to Factor in Your Activity Level

Your natural activity level, or NEAT, also affects how many calories you need to get through the day. If you walk a mile or two to work each day, pace while you talk on the phone, or rarely sit down and relax for more than an hour at a time, your NEAT is probably much higher than someone who’s naturally less active.

Of course, your typical exercise level also affects how many maintenance calories you need. If you work out at least five days a week and go for a long bike ride on weekends, you’ll need more energy per day than someone who lives a more sedentary lifestyle.

To factor in your activity level, determine where you fall in the chart below, and multiply your BMR by one of the following:

  • No Activity: 1.2
  • Light Activity: 1.35
  • Moderate Activity: 1.5
  • Intense Activity: 1.6
  • Extreme Activity: 1.75

The result equals your maintenance calories, or the amount of energy you need to maintain your current weight. You’ll want to decrease your daily calorie intake by as much as 20 percent to lose weight or increase it by up to 500 calories to build muscle.

Ultimately, calculating your maintenance calories isn’t rocket science. Once you’ve determined your TDEE, you can always try increasing or decreasing your daily calorie count slightly to see what works best for you. If you want to keep the math to a minimum, use a calories per day calculator that does the calculations for you to ensure that you’re effectively balancing calorie intake with energy output.

All of the content and media on Lifesum is created and published for information purposes only. It is not intended to be used as a substitute for medical advice or treatment. Users should always consult with a doctor or other health care professional for medical advice. If you have or think you are at risk of developing an eating disorder, do not use the Lifesum app and seek immediate medical help.