How to Set Your Calorie Intake for Building Muscle in 3 Easy Steps

You want to get bigger.

Maybe you’re a skinny guy like me who’s looking to gain mass. Maybe you’re already carrying a decent amount of muscle, but you’re ready to take your physique to the next level.

You’re already lifting weights and training hard. Now you want to create a diet that will help you get even bigger.

You know that you need to eat more calories than you burn to gain weight.

The real question is, how much more?

If you eat too many extra calories, you’ll gain more body fat than you need to. If you don’t eat enough calories, you’ll never get bigger.

Here is a simple three-step process that will help you decide exactly how much to eat if you want to build muscle.

Step 1: Estimate your maintenance calorie intake.

Use Alan Aragon’s total energy expenditure equation to find roughly how many calories you need every day to maintain your weight.

Plug in your current weight as your “target weight.”

Total Energy Expenditure = Target bodyweight in pounds x (8-10 or 9-11 + average total weekly training hours).

You may need to adjust this formula based on your activity levels and gender. If you’re a guy or extremely active, use the upper range of this formula. If you’re a girl or less active, use the lower range. You can learn exactly how to adjust this formula by reading this article.

Let’s use myself as an example.

I weigh 155 pounds, so I’ll enter that as my “target bodyweight.”

I’m extremely hyperactive and fidgety, and have to eat a lot to gain weight. I’m exercising about two hours per day, including strength training. I’m also a guy, in case you didn’t know.

I’m going to use the upper end of the activity multipliers: “11.”

Total Energy Expenditure = [155] x (11 + 14)

Based on this formula, I would need to eat around 3,875 calories per day to maintain my weight.

If you’re a beginner or you haven’t measured your calorie intake for a while, eat at maintenance for 1-2 weeks.

If you haven’t been lifting weights, you’ll probably gain some strength and muscle without a calorie surplus.1,2 If you underestimate your calorie intake, you may accidentally be eating enough calories to gain muscle already.

I averaged about 4,300 calories per day while bulking. If you’re a “hardgainer” like me, you’re going to have to eat a lot more than most formulas tell you.

Read step two to learn how much more.

Step 2: Increase your calorie intake by 10-20%.

There are three reasons you should make small changes to your calorie intake, rather than immediately stuffing your face:

1. You have a very small risk of gaining excess fat.

2. You’ll have a better understanding of your maintenance needs, which will make it easier to adjust your diet when it’s time to lose fat.

3. You don’t have to use any extreme or weird eating habits (e.g. like drinking a gallon of milk a day).

It’s generally best to use percentages to increase your calorie intake, rather than an arbitrary number. However, if you absolutely hate math, adding 200-300 calories per day is a good starting place.

If you gain muscle easily, aren’t very active throughout the day, and tend to gain more fat when you bulk, use the lower end of this range. Increase your calorie intake by about 10%.

If you’re a “hardgainer,” you fidget more than a squirrel on meth, and you can never seem to gain weight, increase your calorie intake by about 20% per day.

If you’re somewhere between those two extremes, add about 15% to your calorie intake.

Let’s use myself as an example again. My predicted calorie intake is about 2,015 per day. If I increase that by 20%, here’s what that would look like:

3,875  x 1.15 = 4,456

Based on the equation, that’s the number I would eat to gain muscle.

Eat at your new target calorie intake for two weeks. If your progress stalls, you need to move on to step three, like I did.

Step 3: Adjust your calorie intake to match your goals and progress.

If your strength and weight haven’t both increased, bump up your calorie intake another 10-20%.

If you’re a hardgainer, you might have to increase your calorie intake more than you think. In some cases, people can burn off about 1,000 calories per day through small movements like fidgeting without realizing it.3

If you start to gain more body fat than you think is reasonable, decrease your calorie intake by about 5-10%. It’s a good idea to take skinfold measurements every 1-2 weeks. This is a simple, fairly accurate way to measure your body fat percentage.4-7

In general, you should see:

  • Your strength increase from workout to workout.
  • Your weight increase every 2-4 weeks, generally by about 1-2 pounds.
  • Your body fat percentage increase slightly.

If you’re an advanced athlete like my friend Holger from the picture at the beginning of this article, you’re going to gain muscle at a slower rate. When you’re close to your genetic potential, focus on increasing your strength rather than your scale weight.

If you’re gaining strength and weight without too much body fat, then keep going until it stops working.

If you’re not gaining weight or strength, you’re either not eating enough or you’re at your genetic limit for gaining muscle.

Train hard, eat more, build muscle.

Let’s recap:

Step 1: Estimate your maintenance calorie needs with Alan Aragon’s total energy expenditure equation. Eat at maintenance for 1-2 weeks.

Step 2: If you haven’t gained muscle or strength, increase your calorie intake by 10-20%.

Step 3: If you still haven’t gained muscle or strength, increase your calorie intake by another 10-20%. Repeat until you’re getting bigger.

If you’re making good progress in the gym, but you’re also getting a little “fluffy,” cut your calorie intake by 5-10%.

Keep monitoring your strength, weight, physique, and body composition, and adjust your calorie intake as needed.

Whether you’re a skinny guy like me trying to build muscle, or a more advanced lifter trying to gain a few more pounds, you need to eat more to get bigger.

It might take some time to figure out how much more you need to eat while gaining as little body fat as possible, but it’s worth it.

Here’s another good question to ask yourself: Do you really need to be this exact about your calorie intake to gain muscle?

It depends, but for most people, no.



1. Donnelly JE, Sharp T, Houmard J, et al. Muscle hypertrophy with large-scale weight loss and resistance training. Am J Clin Nutr. 1993;58(4):561–565.

2. Bryner RW, Ullrich IH, Sauers J, et al. Effects of resistance vs. aerobic training combined with an 800 calorie liquid diet on lean body mass and resting metabolic rate. J Am Coll Nutr. 1999;18(2):115–121. Available at:

3. Levine JA, Eberhardt NL, Jensen MD. Role of nonexercise activity thermogenesis in resistance to fat gain in humans. Science. 1999;283(5399):212–214. Available at:

4. Heyward VH. Evaluation of body composition. Current issues. Sports Med. 1996;22(3):146–156.

5. Brodie DA. Techniques of measurement of body composition. Part I. Sports Med. 1988;5(1):11–40.

6. Orphanidou C, McCargar L, Birmingham CL, Mathieson J, Goldner E. Accuracy of subcutaneous fat measurement: comparison of skinfold calipers, ultrasound, and computed tomography. J Am Diet Assoc. 1994;94(8):855–858.

7. Selkow NM, Pietrosimone BG, Saliba SA. Subcutaneous thigh fat assessment: a comparison of skinfold calipers and ultrasound imaging. J Athl Train. 2011;46(1):50–54. doi:10.4085/1062-6050-46.1.50.

1 Comment

  1. Donald Rose on December 21, 2015 at 1:15 am

    I’m a 62 year old man who has always been skinny, no visible hard muscles, and extremely fidgety and hyperactive. I have never drank alcohol, smoked cigarettes, taken drugs nor have I ever been on medication, and I am never sick. In my twenties, I trained for years with my best friend who looked like a young Arnold Schwarzenegger. Even though we did the same exercises, the more muscle he gained, the skinnier I got. And I was told way back then that I just don’t eat enough to gain any weight or muscle. To this day I still eat like a parakeet. If I try to eat more than a parakeet, I get very sick to my stomach. I drink protein drinks and I’ve even tried creatine (?) but nothing works. Maybe in my next life I’ll look bigger.

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