1. How To Calculate Calorie Intake To Reach Your Goal

Everything you eat and drink contains some energy and sum of these energies is your energy intake. It is measured in kilojoules (kJ) or kilocalories (kcal). This energy intake, or how much you can eat, is the most important aspect to consider if you want to lose, gain or just maintain your current weight.

Everybody is different and has different energy needs. For example, if you have a physically demanding job or do a lot of sport you can eat more without gaining weight as opposed to your friend who sits all day in front of a computer screen. If you struggle with your diet you can use this guide to learn how to calculate calorie intake to optimize it.

small calculator

BMR – Basal Metabolic Rate

The first thing we need to determine is your basal metabolic rate. Simply put this is the amount of energy your body needs to maintain your weight while powering only the vital functions of your body (brain, heart, lungs etc.). This value will be the base of our calculations.

To calculate the BMR we can use these two formulas:

Harris-Benedict formula
Men (in lbs):        BMR = 88 + (6.1 x your weight) + (12.2 x your height in inches) – (5.7 x your age)
Women (in lbs):   BMR = 448 + (4.2 x your weight) + (7.9 x your height in inches) – (4.3 x your age)
Men (in kg):         BMR = 88 + (13.4 x your weight) + (4.8 x your height in cm) – (5.7 x your age)
Women (in kg):    BMR = 448 + (9.2 x your weight) + (3.1 x your height in cm) – (4.3 x your age)

Katch-McArdle formula
Men and women (lbs):  BMR = 370 + (9.8 x lean mass weight)
Men and women (kg):   BMR = 370 + (21.6 x lean mass weight)

Katch-McArdle formula is more accurate but you need to have a good estimate of your body fat. I plan to write an article about that but until then you can use this simple calculator. It uses the U.S. Navy formula for estimating body fat percentage.

Example

My actual measurements are: weight = 137 lbs (62,1 kg), height = 63.5 inches (161 cm), age = 32

BMR according to Harris-Benedict (lbs) = 88 + (6.1 x 137) + (12.2 x 63.5) – (5.7 x 32) = 1516 kcal
BMR according to Harris-Benedict (kg) = 88 + (13.4 x 62.1) + (4.8 x 161) – (5.7 x 32) = 1510 kcal

body fat = around 15%
lean mass = 137 * (1 – 0.15) = 116.45 lbs (52.8 kg)

BMR according to Katch-McArdle (lbs) = 370 + (9.8 x 116.45) = 1511 kcal
BMR according to Katch-McArdle (kg) = 370 + (21.6 x 52.8) = 1510 kcal

In this case the difference between Harris-Benedict and Katch-McArdle is negligible but when I estimated my BMR at the beginning of my get fit journey, the difference was 150 kcal (1750 vs 1600).

The difference was this big because I was very fat and Harris-Benedict formula calculates with your weight which also includes fat. So it overestimates you energy requirements if you carry a lot of fat, as I did.


TDEE – How To Calculate Calorie Intake To Maintain Weight

TDEE stands for Total Daily Energy Expenditure. To estimate it, we need to combine your BMR with your physical activity level like exercise or just moving around. To quantify this activity we will use the physical activity multiplier:

BMR x 1.2 – for sedentary individual
BMR x 1.375 – for lightly active individual (sports activity 2 – 3 days a week)
BMR x 1.55 – for moderately active individual (sports activity 4 – 5 days a week)
BMR x 1.725 – for very active individual (sports activity 6 – 7 days a week)
BMR x 1.9 – for extremely active individual (demanding physical job and sports activity)

Example

Since I’m sedentary for the whole week (in work, on train etc.), except three days when I train, I’m using the multiplier for a lightly active individual:

TDEE = BMR x 1.375 = 1511 x 1.375 = 2077 kcal

So my TDEE is around 2070 kcal which means that If my goal was to maintain weight I would eat around this number of calories.

As I wrote before, it is important to remember that this is just an estimation. You would eat at this energy intake and track your weight (and other measurements) for 2 – 3 weeks and adjust the intake up (if your weight is dropping) or down (if your weight is rising).


Lose belly fat

Cut – How To Calculate Calorie Intake To Lose Weight

Now that we have estimated maintenance calories we can determine fat loss calorie intake. But first, you should decide how fast you want to lose weight. This will affect how much you will have to restrict your energy intake.

There are many good ways how to determine the ideal weight loss target and one of my favourite recommendation is from Greg Nuckols (I think he has a video about this):

body fat % / 20 = % of your bodyweight you can lose weekly without increasing danger of muscle loss

Using myself as an example – 15 % body fat, 137 lbs (62,1 kg):

15 / 20 = 0.75 %

So I can safely lose 0.75 % of my bodyweight per week, which is:

137 x (0.75 / 100) = 1 lbs / week
62,1 x (0.75 / 100) = 0.46 kg / week

Now to calculate my daily calorie intake to lose 1 lbs / week (0.46 kg / week):

suggested daily intake (lbs) = TDEE – deficit = 2077 – (1 x 500) = 1577 kcal
suggested daily intake (kg) = TDEE – deficit = 2077 – (0.46 x 1100) = 1571 kcal

If I choose to lose half of that, the calculation would look like this:

suggested daily intake (lbs) = TDEE – deficit = 2077 – (0,5 x 500) = 1827 kcal
suggested daily intake (kg) = TDEE – deficit = 2077 – (0,23 x 1100) = 1824 kcal

Note on numbers 500 and 1100

Number 500 – I want to burn one pound of fat per week and it takes approximately 3500 kcal to do it. Dividing 3500 / 7 days gives us 500 per day.

Similarly, number 1100 – Burning one kilogram of fat per week takes approximately 7700 kcal, dividing 7700 / 7 days gives us 1100 per day.


Back double bicep pose

Bulk – How To Calculate Calorie Intake To Gain Weight

The first thing we need to determine, similarly to losing weight, is how fast we want to gain weight. The very important thing to consider is your training status because it is one of the factors (others are hormone levels, genetics, supplements (drugs), appropriate training, rest/sleep) determining how much muscle you can build in a given time period. I like the Alan Aragon’s take on this:

Trainee Level Rate of Muscle Gain
Beginner 1 – 1.5% body weight / month
Intermediate 0.5 – 1% body weight / month
Advanced 0.25 – 0.5% body weight / month

These values are for men, women should expect about half of this.

The calculation will be very similar to cut. Let’s say I’m a beginner and because I am a small guy I will use the low end of the range:

1% of 137 lbs (62.1 kg) = 1.37 lbs (0.62 kg)

To calculate my daily calorie intake to gain 1.37 lbs/month (0.46 kg/month):

suggested daily intake (lbs) = TDEE + surplus = 2077 + (1.37 x 200) = 2351 kcal
suggested daily intake (kg) = TDEE + surplus = 2077 + (0.62 x 440) = 2350 kcal

To explain the numbers 200 and 440
  • it is realistic to expect that half of the predicted weight gain is muscle and half fat which means that if we plan to gain 1 lb of muscle we will also gain 1 lb of fat -> bodyweight gain 2 lbs/month
  • to burn or store 1 lb (1 kg) of fat we need 3500 (7700) kcal
  • to build 1 lb (1 kg) of muscle we need 2500 (5500) kcal

Surplus to gain 1 lbs = (1 x 3500) + (1 x 2500) = 6000 kcal / month which is approximately 200 kcal / day
Similarly to gain 1 kg = (1 x 7700) + (1 x 5500) = 13200 kcal / month which is approximately 440 kcal / day


Measuring belly

Adjustments – When Things Don’t Go As Planned

The key to knowing when to adjust is good tracking. In the simplest form, this means to weigh every morning after toilet and before eating or drinking anything.

After a week of daily weigh-ins you would calculate the average weight for the week = (sum of all weights) / 7. After three to four weeks of tracking, you will see if you are losing/gaining weight as predicted. If not you need to make adjustments.

When you are cutting:

  • if you lose weight slower than predicted -> decrease caloric intake
  • if you lose weight faster than predicted -> increase caloric intake
  • recommended increase/decrease is 5 – 10 % of daily caloric intake
  • example: my caloric intake is 1600 kcal -> 5% = 80 kcal, 10% = 160 -> I would use 100 or 150 kcal

When you are bulking:

  • if you gain weight slower than predicted -> increase caloric intake
  • if you gain weight faster than predicted -> decrease caloric intake
  • recommended increase/decrease is 3 – 6 % of daily caloric intake
  • example: my caloric intake is 2350 kcal -> 3% = 70 kcal, 6% = 140 -> I would use 100 kcal

Now that we have calculated our caloric intake, we need to determine our macro breakdown.


I hope you’ll find this guide helpful. If you have any questions, suggestions or experience of your own please feel free to leave a comment:)

6 Comments

  1. Michel

    Thank you for this helpful guide, but shoo what a lot of maths to do!

    I worked out that I need 1831.9 calories per day, which does seem quite a lot, but I suppose depending on what you eat, it can add up.

    When using one of my phone apps, it calculated that I need to eat 1300 calories per day to lose around 2kgs a month.

    Does this sound correct to you? So one would need to drop about 500 calories per day in order to lose a half a kilo a week.

    Reply
    1. admin

      Hi Michel,

      I guess the post looks a bit complicated:) But it’s just 5 calculations you need to do. I plan to add a free excel calculator that will do the math for you.

      Yes, dropping 500 kcal daily to lose half a kilo weekly is correct. I suppose your phone app uses the same math since these calculations are well known:)

      All the best,

      Marek

      Reply
  2. John Rico

    Hey there! I’ve been working out lately to lose weight. I’m doing a lot of cardio and weight lifting. And I’ve been doing this every other day for 3 months now and I noticed that I only lost 2lbs. after that intense training. After I read your guide about calorie intake and I learned that there should be specific calorie intake I should follow to lose weight. I will try to calculate mine and do my best to follow my recommended calorie intake to lose weight. I really appreciate your time for sharing this information.

    Reply
    1. Marek (Post author)

      You’re welcome John!

      Training is great but if you want to lose weight you need to watch how much you eat for sure. I would advise to also watch your protein intake which is very important for preserving muscle mass. To learn more check my other guides. Regarding the cardio, do you enjoy it? If not you don’t need it to lose weight.

      If you have any questions I’ll be glad to help;)
      Marek

      Reply
  3. Lyle

    I’ve actually heard that it’s better to track body fat instead of just going on the scales every week. If you’re improving your diet to make sure you get the right amount of calories then you’re likely to be eating better sources of protein which would lead to muscle mass increase and overall weight increase – at least that’s the theory behind it anyway. I’m not saying weighing is bad but maybe this is just better. I myself I have never tracked this properly but maybe you could and write a blog post about it?

    Reply
    1. Marek (Post author)

      Hello Lyle,

      yes I agree, tracking body fat would be better if it was cheap and easy. Unfortunately it isn’t:) Weighing yourself along with taking weekly or bi-weekly body-part measurements (upper arms, chest, waist, hips, thighs) and progress photos is easy and reliable way to judge your progress. I should rewrite that part of the post or better yet, write a post about progress tracking, as you suggested:)

      Appreciate the comment;)

      Reply

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