How Many Calories Should I Eat to Build Muscle?

September 29, 2021

Step 1: Calculate your BMR (Basal Metabolic Rate)
Step 2: Calculate your TDEE (Total Daily Energy Expenditure)
Step 3:10% calorie surplus
Step 4: Monitor changes in physique
Step 5: Make adjustments as needed

Calculate Your BMR (Basal Metabolic Rate)

Your BMR, or basal metabolic rate, is the number of calories your body burns performing the most basic life sustaining functions. It’s the number of calories your body burns at complete rest, just to stay alive.

There are many different BMR formulas, but the Mifflin-St Jeor equation and the Harris-Benedict equation are the two most popular one’s due to their accuracy.

They will both result in slightly different numbers, but both are great starting points.

You can use both equations and take the average of the two, or choose one of the two to use.

Once you find your BMR using one or both of the equations below, you’ll then use your BMR to find your TDEE.

Harris-Benedict Equation

Men: 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) – (5.677 × age in years)
Women: 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) – (4.330 × age in years)

Mifflin-St Jeor Equation

Men: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
Women: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161

Calculate Your TDEE (Total Daily Energy Expenditure)

To make it easier and avoid any mistakes while doing the math, I’d suggest using this BMR + TDEE calculator. I’ve been using this, and I find it’s accurate for most people. This calculator uses the Harris-Benedict equation.

When you hit “Calculate!” you’ll see it gives you your estimated BMR and your daily calorie needs, which is your TDEE.

If you rather do the math by hand and enter your age, height, and weight into one of the equations above, you can find your TDEE by multiplying your BMR by one of the values below.

Sedentary (little to no exercise + work a desk job) = 1.2
Lightly Active (light exercise 1-3 days/week) = 1.375
Moderately Active (moderate exercise 3-5 days/week) = 1.55
Very Active (heavy exercise 6-7 days/week) = 1.725
Extremely Active (strenuous training 1-2x/day + labor intensive job) = 1.9

Make sure you’re being very honest with how active you are, and the intensity of your exercise. It’s important to use the correct values.

Once you’ve found your TDEE, that is the estimated number of calories your body needs to maintain your current weight at your current activity level. This is what you would call your maintenance calories.

Online TDEE calculators won’t be accurate for everyone. So once you find your estimated TDEE, eat that much for 2-3 weeks, and watch how your weight changes, if at all. If your weight does not change, it’s safe to say that’s your maintenance. If you gain weight, you’re above maintenance, and if you lose weight, you’re below maintenance.

10% Calorie Surplus

Once you’ve found your TDEE, or your maintenance calories, you’ll take 10% of that number, and add that to your TDEE.

Here’s an example:

Let’s say your calculated TDEE is 3,000 calories.

We’re going to take 10% of 3,000 calories, then add that number to 3,000.

3,000 calories x 0.10 = 300 calories

3,000 calories + 300 calories = 3,300 calories.

3,300 calories would likely be a good starting point to gain weight and build muscle at a decent rate during a bulk.

You might see people recommending anywhere from a 10% to 20% calorie surplus. I always recommend starting on the lower end at 10%, and adding more calories if needed.

A beginner who is new to lifting and is very skinny, and has plenty of room to gain body fat, may be better off taking full advantage of the ‘noob gains’ as they call them, and start with a 20% surplus.

But in most cases, I’d rather start with a 10% surplus, and add more food if needed while keeping body fat gain under control. In my opinion, that’s better than adding too many calories too soon, gaining a bit more body fat than intended, and having to reduce calories.

Monitor Changes In Your Physique

Here are some ways you can keep on eye on your progress and how your physique is changing during your bulk.

The scale.
- First thing in the morning, no food or water yet, after using the bathroom, no clothes.
Progress pictures.
- Keep all variables as consistent as possible (distance standing from camera, lighting, angle, time of day, preferably first thing in the morning with no food or water yet, and after using the bathroom).
The mirror.
- The mirror is useful, but it can also be difficult to notice subtle changes when you see yourself nearly every day. That’s why pictures are great.
Body part measurements with a tape measure.
- First thing in the morning, no food or water yet, after using the bathroom.
How your clothes fit.
- If your clothes are getting way too tight too quickly, that could mean you’re gaining too much body fat too quickly, but not always. Use other methods of measuring progress to get a better picture of what’s happening.

I rarely recommend getting a body fat test done because many of them, especially the easily available ones like the scales you step onto and handles you hold at the gym, or your bathroom scale, are very inaccurate.

More accurate methods include 7-site skin fold test (do it 3 times at each spot, take the average), DXA scan, hydrostatic weighing, and air displacement (Bod Pod).

Make Adjustments As Needed

Keep eye on the changes taking place, and make adjustments when necessary.

If you’re gaining weight at just the right rate, keep eating the same amount.

If you’re losing weight, you’ll want to add more calories. If you’re gaining weight too fast, you’ll want to pull back a bit.