How Many Calories Do I Need?

Have you been spinning your wheels trying to lose weight? 

Maybe you’ve tried keto, intermittent fasting or just cutting out junk food. They all work for a little while.. but you end up getting frustrated when you gain the weight back.

Or you’ve been trying to put muscle on, but you aren’t sure how much you need to eat?

You know you need to eat more, but you eat SO MUCH (you probably don’t eat as much as you think, fellow skinny guys and gals trying to gain muscle..) and just can’t seem to get any bigger.

If you’re tired of not making progress, and want a more accurate way of figuring out how many calories you need for your goals, then this article is for you.

What is a calorie, anyway?

A calorie is a measurement of energy. 

All food is made up of calories, and how many calories a food has determines how much energy your body can use from it.

You need to eat a certain amount of calories every day to give your body enough fuel to think, breathe, go to work, and crush that workout you have planned.

If you eat more calories than you burn, your body will store that extra energy as fat tissue, which it can burn for energy later if it needs to. 

If you eat the same amount of calories as you burn, you’ll maintain your weight.

This is called an energy balance. 

Think about energy balance like a scale. When that scale is balanced, you will maintain your weight.

To achieve energy balance, calories in (the calories from the food you eat) must equal calories out (the calories you burn).

Calories in..

The calories in part of the equation is relatively simple. It’s how many calories you eat.*

*It’s actually a bit more complicated. A few things can affect the calories in part of the equation..

For one thing, the FDA allows for a 20% margin of error in prepackaged foods (1). You might think you ate a 200 calorie bag of potato chips, but they were actually 240 calories. 

Additionally, research has shown a slight difference in the amount of calories absorbed based on how foods are prepared (2). For example, a study done on almonds showed that more calories were absorbed from almond butter compared to almonds. 

Your body also requires a varying amount of energy to break down different types of foods (more on that in a minute..).

Even with that said, you can still get a very good estimate of how many calories you are eating by reading nutrition labels and/or weighing the food you eat.

Calories out..

How many calories you burn per day is your metabolism.

The word metabolism is thrown around a lot, but I think many people don’t really know what it is. 

It’s made up of four components:

Basal metabolic rate (BMR)- Your body needs a certain amount of calories every day to “keep the lights on”. This is called your basal metabolic rate, and it’s the amount of calories you need to eat to do all your basic functions like breathe, think, keep your heart beating, blink, etc.

Non-exercise associated thermogenesis (NEAT)- This is the amount of energy you expend by doing normal daily activities like working, walking, driving, etc. 

Exercise associated thermogenesis (EAT)- The amount of calories you burn due to planned exercise. This is actually much lower than most people assume it is. It’s why you might hear the saying “you can’t out-train a bad diet”. It’s not technically true to say that, because if you worked out for hours and hours on end you could burn enough calories per day to eat basically whatever you want (an example of this is an athlete like Micheal Phelps, who while training for the 2008 Olympic games was eating upwards of 10,000 calories per day). However, unless you are working out multiple times per day, every day, the amount of calories you burn during your workouts probably won’t add up to as much as you would think.

Thermic effect of food (TEF)- This is how many calories you burn while digesting food. Different macronutrients (protein, carbohydrates, and fats) burn different amounts of calories. Protein takes the most calories to burn, followed by carbohydrates and fats. Contrary to what some people believe, meal frequency does not have an effect on your metabolism (3, 4). TEF makes up about 15% of total calorie burn. Whether you eat six meals per day or two, 15% is still 15%! 

Now let’s figure out how many calories you need!

The simple method

A simple method of estimating calorie needs is to use a calorie per weight range. 

Use the following guidelines based on your activity level:

• • 12-14 calories/lb of bodyweight for normal, healthy individuals who get very little physical activity and spend most of the day sitting
  • 14-16 calories/lb for people who workout 3-5 times per week and have fairly active lifestyles
  • 16-18 calories/lb for people who work very active jobs and workout 4-5 times per week

To figure out how many calories you need, simply multiply your body weight by the calorie range that is the best fit for you.

For example, let’s calculate the maintenance calories of a 6 foot tall 32 year old male who weighs 185 lbs, works a desk job, and strength trains 3-4 times per week. We’ll call him Bob.

185 x 15 calories per pound = 2,775 calories. 

The more complicated method

If you like doing math, or you want a *slightly* more accurate estimate of your maintenance calories, you can use one of the equations below to figure out your basal metabolic rate. You’ll then multiply your estimated BMR by an activity multiplier (which takes into account your EAT and NEAT).

If you don’t know your current body fat percentage, you can use the Mifflin-St. Jeor equation:

Men: BMR = [9.99 x weight (kg)] + [6.25 x height (cm)] – [4.92 x age (years)] + 5

Women: BMR= [9.99 x weight (kg)] + [6.25 x height (cm)] – [4.92 x age (years)] – 161

So for Bob, who is 6ft tall (183cm), 32 years old, and weighs 185lb (84kg), his BMR would be calculated like so:

BMR = [9.99 x 84kg = 839.16] + [6.25 x 183cm = 1,143.75] – [4.92 x 32 = 157.44] + 5 = 1,830.47 calories.

The Katch-McArdle equation is generally considered more accurate for people who are already relatively lean because it takes current body fat percentage into account:

BMR = 370 + (21.6 x LBM) where LBM = [total weight (kg) x (100 – body fat %)] / 100

Let’s pretend that in our example, Bob is 12% body fat. His estimated BMR would be the following: 

BMR = 370 + (21.6 x 73.92) = 1,966.67 calories

Once you find your estimated BMR, you need to multiply that number by one of the activity multipliers below:

• • 1.2 = Sedentary (working a desk job and very little exercise)
  • 1.3-1.4 = Mostly sedentary (working a desk job during the day and exercising 1-3 times per week)
  • 1.5-1.6 = Active (moving around during the day and training intensely 2-4 times per week)
  • 1.7-1.8 = Intense training (demanding job and training 3-5 times per week)
  • 1.9-2.2 = Extremely active/athlete (very physical job or professional athlete and training intensely 4-6 times per week) 

So which method is best?

Using the Mifflin-St. Jeor equation plus an activity multiplier of 1.4, Bob’s maintenance calories would be 2,563.

Using the Katch-McArdle equation plus an activity multiplier of 1.4, Bob’s maintenance calories would be 2,753.

Remember that using the simple method, Bob’s maintenance calories were 2,775.

What do you notice about those three numbers?

Hopefully you see that they aren’t all that different.

Which calculation you choose doesn’t matter that much. The goal is to get a ballpark estimate as a starting point. 

How do I lose weight? Or gain muscle?

Once you’ve figured out your maintenance calories, you can adjust that number based on your goal. 

It’s not a great idea to just add or subtract an arbitrary number of calories, like 500.

The reason is that if your maintenance calories are 1,500, 500 calories is a much bigger percentage than if your maintenance calories are 3,500. It’s much better to add or subtract a percentage of your maintenance calories.

In general, adding between 20-40% of your maintenance calories if you’re a beginner and 10-20% if you’re an intermediate to advanced lifter looking to add mass is a good place to start. Subtracting 10-30% of maintenance calories is usually a good place to start if you’re looking to lose weight. 

Let’s say Bob wants to add muscle to his frame. If we estimate his maintenance calories at 2,753, and he adds 10% of his maintenance calories (275 calories), Bob is looking at a calorie surplus of 3,028 calories. 

Conversely, if Bob wants to get shredded for the summer, he can subtract 20% of his maintenance (515 calories), putting him in a calorie deficit of 2,238 calories. 

Does it matter what I eat?

Once you figure out how much to eat for your goals, the next thing you need to do is figure out what to eat.

I’m not going to tell you exactly what foods you should eat (that should be individual and based on the foods you actually like). I will give you some guidelines on how much of each macronutrient you should aim for. 

Macronutrients are protein, carbohydrates, and fats (and also alcohol).

All foods are made up of a ratio of these three macronutrients (and alcohol is made of… drumroll please…alcohol! And some carbohydrates, depending on what you drink).

Boneless, skinless chicken breast is mostly protein with a little bit of fat and no carbohydrates, usually about 80% protein and 20% fat. Protein is important for building and maintaining muscle, as well as the creation of other cells in the body. 

Protein also has the highest TEF of all the macronutrients* (remember- that means the amount of calories your body has to expend in order to break food down). 

*Actually, alcohol has a similar TEF to protein. That DOESN’T mean you should start pounding back drinks every day. Remember, TEF only accounts for about 15% of total daily energy expenditure!  

As a very general guideline, you should aim to get around one gram per pound of lean body mass. If you don’t know your lean body mass, you can also use your goal body weight. 

For example, let’s say you weigh 180 lbs and you want to lose 15 lbs. You can aim for 165 grams of protein every day.

Nuts and nut butters like cashews and peanut butter are examples of mostly fat sources, with approximately 70% of their calories coming from fat, 20% coming from carbohydrates and 10% coming from protein. Dietary fat helps to regulate hormones, absorb vitamins and minerals and provide the body with energy.

Shoot for about 0.3 to 1 gram per pound of lean body mass. If you’re looking to add muscle, It’s probably a good idea to stick to the lower end of the range so that you can make room for more carbohydrates. When you are in a calorie surplus, your body is more likely to store excess calories as fat from fat than it is from carbohydrates (5). 

Rice and potatoes are mostly carbohydrate sources, with about 80% of the calories coming from carbohydrate, 5-10% from protein, and 1-5% from fat. Carbohydrates are your body’s preferred source of energy. 

While there aren’t specific carbohydrate recommendations you need to follow (you can survive on a diet of almost exclusively protein and fats, like the ketogenic diet or the carnivore diet), having enough carbohydrates in your diet will help make sure you have enough energy for your workouts. 

The amount of carbs you need can be figured out by first calculating the amount of protein and fat you need, and then subtracting the calories that come from both from your overall calorie needs.

Don’t worry, I’ll walk you through an example in a minute. 

Protein and carbohydrates both contain four calories per gram, and fat contains nine calories per gram. Once you figure out your protein, fat, and carbohydrate requirements, you’ll multiply them by four, nine, and four, respectively.

Example

Let’s bring back our example, Bob.

Bob is trying to get shredded for the summer, and if you recall, we estimated his calorie deficit at 2,238 calories.

To figure out his macronutrient requirements, we can start by figuring out how much protein he should eat. 

If Bob is 185 lbs and 12% body fat, that means his lean body mass is 162.8 (185 – 12% = 22.2).*

*Remember, If you don’t know your lean body mass, you can use your goal body weight OR you can estimate your body fat percentage by looking at photos online. An estimate is all you need here!

We can round this up to 165 grams of protein per day. 

165 x 4 = 660. This means that 660 calories are going to come from protein.

Next, we’ll calculate fat. Bob prefers carbohydrate heavy foods like rice and potatoes, so we’re going to keep his fats on the lower end of the range to give him plenty of room for carbohydrates.

0.3 x 165 = 49.5, which we can round to 50 grams of fat per day. 

50 x 9 = 450. This means that 450 calories are going to come from fat.

To figure out Bob’s carbohydrate requirements, we are going to add the calories from protein and fat, and what’s left over will go to carbohydrates.

660 + 450 = 1,110 calories.

2,238 – 1,110 = 1,128 calories.

1,128 / 4 calories = 282 grams of carbohydrates.

Hate doing math?

You can use my calorie calculator below to figure out how many calories you need. No math needed.

Cal’s Calorie Calculator

Wrapping up

Remember, these are just estimates to get a starting point. Don’t stress out over which calculation you use or what percentage of a surplus or deficit you start with. No calculation is going to be 100% accurate. 

What is important is that you pick one and try it for a month. Track your weight (every day) and adjust if needed.

If you aren’t losing or gaining weight, first make sure you are tracking everything accurately.

If you’re absolutely sure that you’re tracking everything correctly, then make an adjustment to your surplus or deficit and track for another month.