How many calories do I need to build muscle?

For all us hard gainers we need to monitor our energy input from food and the amount of energy we need depends on our basal metabolic rate and our activity levels. The focus of this article is to answer the question, How many calories do I need to build muscle? There are a few things we need to look at first before we answer this question, so please do continue reading.

Kilocalories “The fuel for your tank”

Energy intake and output is measured in kilo calories. The amount of energy food contains per gram is known as it’s energy density. You will find calorie (cal) displayed on the food’s nutrition label and it is given per 100 grams of the product. One Kilocalorie is equal 1000 calories. Next time you eat look at the nutrition label, you will see how many calories are contained in the food.

Here is a short video looking at a food label and an explanation of calories and energy.

The Hard gainers calorie needs are different to those who gain weight easily. We need to be in a surplus! Rather than in a maintenance or deficit of calories. I will look into this later when we go into the basal metabolic rate calculator or BMR for short.

The foods we get our calories from

healthy food for energy

The food’s from which we get our calories from fall into 4 groups:

  • Protein – Contains 4 calories per gram
  • Carbohydrates – 4 calories per gram
  • Fats – 9 calories per gram
  • Alcohol – 7 calories per gram.

Let’s take a quick look into food and the recommended guidelines.

  • Fruit and vegetables (Vitamins) – At least 5 a day
  • Bread, rice, pasta, potatoes (carbohydrate, fiber) – At least one of these type of food with each meal
  • Meat, fish, eggs, beans, nuts (Protein) – Eat with every meal to get protein, choose lower fat options, reduce red meat and processed options
  • Milk and dairy – Eat some but choose lower fat options
  • Foods and drinks high in fat and sugar – use minimally in order to reduce unhealthy weight gain.
  • Adequate hydration from water as it is essential for life, health and performance. Aim for 2 liters per day.

Calorie and energy needs 4 the hard gainer!

Let’s look at energy intake and energy output:

  • Energy Intake – This refers to the sources from which you take in energy, simply put the food and drink you consume daily.
  • Energy output – Energy output refers to how you use energy and also includes your resting metabolic rate (RMR), which is the amount of energy you use at rest. Typical ways of increasing your energy output would be through exercise, or daily activities like walking, cleaning and even talking.

The resting metabolic rate (RMR) tends to be higher in us hardgainers. We burn or use more calories at rest than most as we have a fast metabolism. Please take note that when energy input exceeds energy output there will be weight gain. Body weight increases either through fat or muscle. This is where we want to be if increasing muscle size and strength is our goal.

  • Energy input > energy output = Weight gain.

Unfortunately as hardgainers we are naturally in a state where our energy input is always less than our output

  • Energy input < energy output = “Weight loss Hardgainers”

Some of us tend to be in a state where energy input and output are the same which results in weight maintenance meaning there is no progress in muscle size or strength, we remain the same for a very long time and make little to no progress.

Basal metabolic rate calculator

There is a formula for calculating your BMR which is the amount of calories your body burns at rest for basic functioning. The BMR formula uses your height, weight, age and gender as variables. This is much more accurate than just calculating calorie needs based on body weight alone. To really determine our energy needs it’s a good idea to use this equation.

  • MEN: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.8 x age in years)
  • WOMEN BMR = 655 + (4.35 x weight in pounds) + ( 4.7 x height in inches) – (4.7 x age in years)

Different activities also expend different levels of energy. Below I will show you the approximate number of calories burned per hour during participation in various activities for the average male (79kg) and the average female (65kg).


Weightlifting-               474kcals

Brisk walking-             395kcals

Dancing –                     356kcals

Light outdoor cycling – 447kcals

Jogging  –                     553kcals


Weightlifting –               390kcals

Brisk walking –              325kcals

Dancing –                     293kcals

Light outdoor cycling – 390kcals

Jogging –                      455kcals

OK so lets first of all work out Basal metabolic rate (BMR) for a 168Ib, 5ft 10 inches, 35 year old male.

  • 66 + (6.23 x 168Ibs) + (12.7 x 70inches) – (6.8 x 35 years old) =
  • 66 + 1046.64 + 889 – 238 = 1,763 (BMR)

So 1763 calories are needed for this individual at rest without taking into consideration his lifestyle and activity levels.

To really determine your bodies energy needs, our levels of exercises need to be accounted for. Once you have worked out your BMR using the formula above it should than be adjusted by factoring in the amount of exercise taken on a regular basis.

Amount of exercise and daily calories needed

  • Little/ none –                                                           BMR X 1.2
  • Light (1-3 days a week)  –                                     BMR X 1.375
  • Moderate (3-5 days a week)   –                             BMR X 1.55
  • Heavy (6-7 days a week) –                                     BMR X 1.725
  • Very heavy intense (workout twice a day) –       BMR X 1.9

As hard gainers we will be training 3 to 5 days a week so will use the moderate multiplier. Taking into account the above BMR of 1763:

  • 1763(BMR) x 1.55 = 2732.65 calories

So this is the amount of calories needed by the gentleman just to maintain himself. As we are hardgainers I would recommend that once you work out your BMR and multiplying it by 1.55, you should further add another 250 calories per day. Adding 250cal takes the total calories to 2982.65 calories per day. This is great if you want to gradually increase your muscle mass and strength. As you will not only be burning calories through exercise but also at rest. We as hard gainers have a very fast metabolism. The extra calories will make sure you are always in an anabolic environment.

If you find no success after 1 to 2 months in your attempts to gain muscle and strength I would recommend you to increase your calorie intake by a further 250 calories per day. Increasing calories could be done by adding an extra meal per day or even eating frequent small meals.

So how many calories do I need to build muscle? The answer to this question is an extra 250 calories per day! Work out your BMR and multiply it by your activity level. You can keep a track of how many calories you consume daily in a diary, most food’s show how many calories they contain on their nutrition label. Please remember it also depends on how active you have been throughout the day, if you have been jogging remember this burns 553kcals per hour, so you may have to increase your intake further.

OK now lets look at the anabolic environment as it is very important in building muscle!

Anabolic Environment

man lifting weights

There are two states that your body keeps fluctuating between and you need to maintain a fine balance. These are the anabolic environment and the catabolic environment. The anabolic state is where the body builds and repairs muscle tissue which is the opposite of the catabolic state. The catabolic environment involves the process of breaking down tissue to replenish depleted energy levels of the body. So the catabolic process provides the energy for anabolism to occur.

We hard gainers want to shift our body to a more anabolic state so we need a calorie surplus from food to provide our muscles with the energy needed for them to grow and repair. Without creating the correct balance of nutrition, rest and exercise the body will be unable to fulfill it’s energy requirements.

For us hard gainers to remain in an anabolic state we need a calorie surplus. As our energy needs are greater. If we do not have enough calories our body will break down tissue to use as energy. This will leave us in a state similar to a dog trying to chase his tail. We get no where or remain where we are.

We do not want to break down our precious muscle tissue we worked so hard to get. Unfortunately this is the response to depleting energy levels in our body.


If your looking to achieve that muscular body it is crucial to remain in an anabolic state. By adding an extra 250kcals to your day. This caloric surplus can be introduced gradually through small changes. It has worked for me and I have noticed an increase in size and strength.

  • Use the basal metabolic rate formula to work out your resting calorie needs
  • Multiply by the exercise multiplier
  • Once you have the total add a further 250 cals to your daily intake

Keep a daily food diary to keep track of your calories. Remember not to stuff yourself with unhealthy food choices. Always select wholesome, unrefined, unprocessed and natural food choices and keep away from trans fats.

I hope I have answered the question, How many calories do I need to build muscle? Please leave your comments below and if you decide to take the approach I have taken by increasing calories, let me know how it worked out for you.