Eating to Grow

How to Calculate Macros (Macronutrients) for Lean Bulking

If you want to build size there is only one sure way to do so and that is to eat in a caloric surplus. In order to ensure you are in a surplus, you must first know your maintenance calories. Once you have your maintenance calories or at least an idea of what they are, you will be a few short calculations away from creating a well balanced caloric intake and macronutrient spit.

What are macronutrients: Nutrients that the body uses in relatively large amounts – proteins, carbohydrates, and fats. This is as opposed to micronutrients, which the body requires in smaller amounts, such as vitamins and minerals. Macronutrients provide calories to the body as well as performing other functions.

Note: In order to calculate your EXACT maintenance level and establish a “perfect” macronutrient split for yourself can be time consuming, expensive, and simply not worth the efforts. This is why I have chosen to give you a simple and very basic starting point that will do the trick.

Simple way to calculate your caloric maintenance level

If you are a male with a healthy metabolism who exercises regularly then the number 16 is a great place to start. Simply multiply your current bodyweight x 16 to get an estimated caloric maintenance level. If you are not as active with a sluggish metabolism, 14-15 may work better for you.

Where does this number come from?

Resting Metabolic Rate: Your resting metabolic rate is approximately 10-11 calories per pound of bodyweight.

Thermic Affect of Activity: This is roughly 10-20% for someone who lifts weights regularly.

Thermic Affect of Food: Food has to be digested thus requires calories to do so. This is approximately another 10%.

Calculating your maintenance calories


170 lbs x 16 = 2,720 Calories per day to maintain your current weight.

Creating a caloric surplus

The larger the surplus, the more weight you will gain, faster. Do not confuse weight with lean muscle tissue. If you are interested in gaining lean mass while avoiding losing your six pack over night then I would recommend a smaller surplus. A surplus of anything from 100-500 calories per day is the standard.

I recommend a 250 calories per day surplus for a steady weight gain while avoiding packing on too much fat during your bulk.

Example of a caloric surplus:

2,720 maintenance calories + 250 caloric surplus = 2,970 calories per day to build size

Calculating your protein intake

The rule of thumb for adequate daily protein intake is 1 gram per pound of bodyweight. Some may require a little less, some could benefit from a little more. Anything from 0.8-1.5 grams per pound of bodyweight is typical.

Note: If you are sensitive to carbohydrates I would recommend using the higher end of the protein formula. This will allow you to meet your caloric surplus without consuming too many carbohydrates.


1.2 x 170 lbs = 204 grams of protein per day

Calculating your fat intake

Fat intake is also determined using a very simple formula. The rule of thumb here is 0.25-0.5 grams per pound of bodyweight. I tend to think that 0.25 is a little too low but nonetheless, it is up to you.

Note: Increased fat consumption will also decrease total carbohydrate consumption for the day.


0.5 x 170 lbs = 85 grams of fat per day

Calculating you carbohydrate intake

This is, in my opinion, the easiest part of it all. Your carbohydrates will come from the remaining calories.

Step 1: Convert your daily protein into calories. There are 4 calories per gram of protein.

204 (grams of protein) x 4 = 816 calories

Step 2: Convert your daily fats into calories. There are 9 calories per gram of fat.

85 (grams of fat) x 9 = 765 calories

Step 3: Figure out how many daily calories are left over.

2,970 (daily calories) – 816 – 765 = 1,389 Calories left over

Step 4: Convert your calories into grams of carbohydrates. There are 4 calories in each gram of carbohydrates.

1,389 / 4 = 347.25 grams of carbohydrates.

Macronutrient Split

347 Carbs
204 Protein
85   Fats

Tracking you calories and macronutrients

If you are planning on simply writing everything down in a log and tracking your intake that way, that is totally fine. However, if you want to make things much simpler on yourself, download an app called My Fitness Pal to your cell phone, ipod, ipad, or computer. This will not only allow you to input all of your foods as you consume them, but it will also calculate all of your calories and macronutrients for you. Now, this is not the only application available for this purpose, but it’s the one I use and find that most people use as well.

Food for though

If you recall the beginning of this post I mentioned micronutrients. These consist of your vitamins, minerals, and (for some) fiber intake. So before you get the idea that you can attempt to meet your macronutrients for the day consuming pizza and cake, you have to consider your micronutrients. It is very important that we include a good amount of fruits and vegetables in our diet along with hitting about 30-50 grams of fiber per day.

If you take all of these factors into account, you will soon realize that creating a macronutrient-tracking based diet is a great way to maintain a healthy and well balanced diet without completely blacklisting your favorite foods.