Calorie control is important for weight control. Whether you’re trying to lose, gain, or maintain your weight, calories count! Whether you’re counting meticulously or just curious, it’s a good idea to know how to calculate your calorie needs.
Related Reading: What is a Calorie?
Calories = Energy
To know what we are calculating, we need to understand how our body uses energy throughout the day. Even just sitting there reading this article, your cells are hard at work using up energy. Breathing, digesting, and especially exercising all use energy – which we call “burning calories.” The more active you are, the more calories you’re burning throughout the day. Plus, muscle burns more than fat just by existing (!!!), so your body composition (the ratio of muscle to fat) matters.
Every person is different when it comes to how much energy we use in a day. The average amount is about 2,000 calories worth of energy. But a little old lady and a bodybuilder are obviously not both going to be burning 2,000 calories! Depending on your weight, height, sex, activity level, and body composition, we can get a pretty close estimate as to how many calories you burn in a day.
How to Calculate Your Calorie Needs
There are a few pieces of information you’ll need before you can calculate your calorie needs:
- Your height
- Your weight
- Your age
- Your sex
- Your activity level (Don’t worry – the calculator I link to will help you determine that!)
The simplest way to get an estimate of your calorie needs is to plug your data into an online calculator. Click here to use an online calculator to find your calorie needs! I like this website because it offers other estimates based on if you were change your activity level all on one page, you don’t need to sign up for anything, and it takes, like, 30 seconds.
Another way to calculate your calorie needs is by using a formula. There are a couple of them out there, but I like the Harris-Benedict Formula. I don’t know how they came up with this stuff, but it’s easy to plug your information in, put it in a calculator (or google, which can be used as a calculator..did you know that?) and add ’em up.
This method requires two steps. First, you’ll use the formula to find your BMR, or BEE. That’s basal metabolic rate, or basal energy expenditure. That’s how many calories you burn if you do nothing but lay in bed all day. Next, you’ll multiply by an activity factor to get your TEE – total energy expenditure. That’s how many calories you burn when you’ve been moving around or exercising. Your TEE is a more accurate representation of your real calorie needs, because most of us don’t lay in bed all day every day!
Step 1: Calculate your BMR/BEE using the Harris-Benedict Formula:
Men: 66 + ( 6.2 × weight in pounds ) + ( 12.7 × height in inches ) – ( 6.76 × age in years )
Women: 655.1 + ( 4.35 × weight in pounds ) + ( 4.7 × height in inches ) – ( 4.7 × age in years )
(Sorry, metric users. Here, have a link for your equation using kg and cm :))
Obviously, that formula looks a little intimidating. It’s really quite simple if you know your PEMDAS rules! Calculate all of your items in parentheses first, then add/subtract all the way across.
Example: 25 year old female, 5’4, 135lbs.
BMR = 655.1 + ( 4.35 × 135 ) + ( 4.7 × 64 ) – ( 4.7 × 25 )
BMR = 1426 calories
Step 2: Multiply your BMR/BEE by 1.5 to get an estimate of your TEE.
TEE = BMR x 1.5
TEE = 1426 x 1.5
TEE = 2139 calories
Boom. You have an estimate of how many calories you burn every day!
Just to double check myself, I threw my example girl’s information into the online calculator with moderate exercise. According to the calculator, she burns around 2081 calories per day – a difference of about 60 calories. Not bad!
What do I do with my calorie needs now that I’ve calculated them?
“Okay, Amy,” you ask, “Why are we doing all of this math? Literally no one does math for fun except you.”
Your calorie needs indicate how many calories you burn in a day. Therefore, if you wanted to maintain your current weight, you would eat that many calories!
Remember – If you eat as many calories as you burn, you maintain your current weight. If you eat more calories than you burn, your body will store the extra calories as fat. If you burn more calories than you eat, your body will use up your fat (and muscle) stores for extra energy.
So, depending on your current weight goal (gain, maintain, or lose), you need to adjust your calorie intake accordingly.
Adjusting Calories to Gain or Lose Weight
Many of us set goals when we are trying to adjust our weights. For most of us, we are trying to lose weight and set a goal like “I will lose 1 pound every week for twenty weeks so I will lose 20 pounds!” That’s a great goal! It might sound slow, but it’s actually a good pace to lose half a pound to two pounds per week.
How many calories in a pound?
How can we turn calories burned into a pound of body weight lost? Well, actually, that’s easy! There’s a nice, clean conversion:
3,500 calories = 1 lb
This pound can be from fat or from muscle. When your body stores energy (from eating more calories than you burn), it stores it as fat or in muscles. When we eat fewer calories than we need, our body pulls the energy from both fat and muscle to make up for it. That’s why it’s so important to keep your muscles strong by exercising while restricting your calories!
It’s important to know your calorie needs – TDEE – using the online calculator or the Harris Benedict Formula because you need a starting point from which to adjust.
If you wanted to lose one pound a week, you would need you eat 3,500 fewer calories that week. Over the span of seven days, that’s 500 fewer calories each day.
Example: Say our example girl from above wanted to lose 5 pounds at one pound per week. We calculated her TDEE at about 2100 calories.
3500 calories/week / 7 days/week = 500 calories/day
2100 calories – 500 calories = 1600 calories
Example girl could eat 1600 calories for five weeks to lose five pounds. Cool!
What if I’m not trying to gain or lose weight?
You have less math to do! Now that you know your calorie needs, all you need to do is balance what you eat to maintain your current weight. Woohoo!
How do I know how many calories I’m eating in a day?
There are many ways you can keep track of the calories you consume. I like to use an app on my phone, or you can use a website application, or even just do a little math and keep a journal! Here are a couple websites to get you started:
My Fitness Pal – A food journal application and website. Forums to help you stay encouraged. Make friends to stay accountable. Scan barcodes to automatically enter food. So easy!
Supertracker – A food journal website that follows the USDA guidelines of MyPlate.
Related Reading: MyPlate – The US Recommendations for Diet Planning
You’ll need to know how to read a nutrition facts label to keep track of your calories. You’ll also need to know portion sizes. Weighing and measuring food ensures you are counting calories accurately! An apple that weighs 100g will have fewer calories than an apple that weighs 180g! Here are some resources to help you with those:
If you’ve never counted calories before, I challenge you to do it for a day, or even just a meal. Sign up for a calorie tracking site and just see what it’s like. You might find that it’s not as daunting as you thought, or be surprised to find out just how many calories are in your favorite food (or how few are in your second favorite food!)
How to Calculate Your Calorie Needs: Recap!
Calories = Energy.
Calories In > Calories Out = Weight Gain
Calories In < Calories Out = Weight Loss
Calories In = Calories Out = Weight Maintenance
To calculate your needs, you can:
- Use an online calculator like this one
- Use a formula, like the Harris-Benedict Formula
Plug in your age, height, weight, sex, and activity level to either the online calculator or the formula. The online calculator will give you your total energy expenditure (TEE). The Harris-Benedict Formula will give you your basal energy expenditure (BMR/BEE). If you use the formula, you’ll need to multiple your result by 1.5 to get your TEE. Try them both! You’ll get numbers close to each other.
To gain or lose weight, you should know that:
3,500 calories = 1 lb
and you can add or subtract calories to get to that point. To lose one pound a week, subtract 500 calories per day from your TEE. (500 calories over 7 days = 3,500!)
Keep track of your calories using a journal, app, or website. Understand how to read a nutrition facts label and portion sizes. Weighing and measuring food ensures you are counting calories accurately!
Are you overwhelmed? I hope not. It’s easy, but I have done this a lot in my personal life and my school work! If you need help calculating your needs, understanding how many calories to cut back on to lose weight, or just need help setting some goals, please contact me! I am more than happy to help you! You can find my contact information in the sidebar under my photo. 🙂