Flexible Dieting: How to Calculate Your Macros

“What are your macros?” This is one of my favorite questions to ask and one of the more common ones I get asked.

Macros, short for macronutrients (proteins, fats, and carbohydrates), form the basis of Flexible Dieting/IIFYM. These macros are the basis of all calories you consume.

Before you read this make sure you’ve read the article What is Flexible Dieting?.

Calculating and adjusting your daily macro goals is both the bread and butter basics and something you never really graduate from as a Flexible Dieter.

Starting out with Flexible Dieting this seems a lot more complicated than it really is.

Your ability to calculate and adjust your macros correctly will largely determine whether or not you reach your physique goals with Flexible Dieting.

Everybody is different (yes, you are a unique snowflake…) so calculating your macros is just the beginning. And even the most experienced coaches working with clients may get it wrong to start with.

Each person’s metabolism, overall health, and lifestyle all play a vital role in how much energy we actually burn and how much of each macronutrient we should be eating.

But starting with some solid guidelines, even if it isn’t quite right, can be a good start on your journey to dominate your goals, and getting the body you want.

So Where Do You Start?

TDEE

photo credit: JD Hancock via photopin cc

When getting started with Flexible Dieting the most important thing to calculate is your TDEE (Total Daily Energy Expenditure).

I’ve written more about that here, but basically it’s the amount of calories you burn in a day. Consistently eat less than this and you lose weight or eat more than this and you gain weight.

Please try out our Macro calculator here.

Basic Formula

The Mifflin, M. D., St Jeor formula is one of the most popular and one of the most respected methods used to calculate your TDEE. Here is the formula used to calculate your Resting Energy Expenditure (REE), which is the energy it takes to run your body without any movement.

Here’s what the formula looks like.

For males:

10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) + 5 = REE

For females:

10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) – 161 = REE

Tip: Remember your high school math lesson about Order of Operations: (PEMDAS from left to right) when solving the equation for yourself.

Since most people don’t lie in bed all day doing absolutely nothing, we next have to figure out movement expenditure or TDEE

  • Sedentary
    Just normal everyday activity like a little walking, a couple flights of stairs, eating, talking etc. (REE X 1.2)
  • Light activity
    Any activity that burns an additional 200-400 calories for females or 250-500 calories for males more than your sedentary amount. (REE x 1.375)
  • Moderate activity
    Any activity that burns an additional 400-650 calories for females or 500-800 calories for males more than your sedentary amount. (REE x 1.55)
  • Very Active
    Any activity that burns more than about 650 calories for females or more than 800 calories for males in addition to your sedentary amount. (REE x 1.725)

For those with varied exercise, a more fluid approach can be used. You use your sedentary TDEE as a base and then track your exercise allowing your TDEE to be adjusted based on the amount of exercise you do on a given day. However, this does make tracking your macros a little more difficult. 

A typical TDEE equation could look like this:

Let’s say you’re a 29-year-old, 183 cm, 88 kg, very active male.

Here’s your equation with results rounded to nearest whole number:

(10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) + 5 = REE) x 1.725 = TDEE

10 x 88 + 6.25 x 183 – 5 x 29 + 5 = REE

880 + 1144 – 145 + 5 = 1884 (REE)

1884 x 1.725 = 3250 (Very Active TDEE)

Your TDEE would be around 3,250 Calories.

  • Eat more than this = weight gain.
  • Eat less than this = weight loss.
  • Eat this amount = weight maintenance.

As I mentioned, it’s sometimes not as black and white for all people, but for simplicity’s sake let’s imagine it is.

If you want to lose weight I recommend dropping your overall calories by no more than 20% to start with – So in the example, this would take the guys calories from 3,250 to 2,600 for weight loss.

3,250 – (3250 x .20) = Weight Loss TDEE

If you’re looking to gain weight then add 20% calories to your overall intake. So in the example, this would take the guys calories from 3,250 to 3,900 for weight gain.

3,250 + (3250 x .20) = Weight Gain TDEE

Hate all the math? We do all of this for you with our IIFYM Macro Calculator.

With this knowledge alone you could get started towards your goal. Counting calories can be a very effective way to lose weight (here are some stories of others who’ve done this).

I’ve found losing weight and losing fat can be two different things (you can lose muscle too), hence the importance of measuring each macronutrient.

Basic Formula Exceptions

  1. The Very Lean
    For those with very little body fat and a high proportion of lean body mass, the standard IIFYM formula isn’t best. The standard formula factors in an average body fat percentage, so those with below average will have a lower TDEE calculated with the standard formula than would be typical. Muscle tissue burns more calories even at rest, therefore, should be accounted for. When using our macro calculator, simply use the “Lean Mass” setting. This switches to McArdle, Katch Formula which is the most accurate for those with low body fat.
  2. The Obese
    Just like the very lean, the very heavy have an above average body fat percentage and this also skews the standard formula’s results. Fat tissue isn’t active tissue and requires very little energy to maintain itself. For obese individuals, total fat weight should be considered in the equation. Here’s a more in-depth article that discusses how IIFYM works for obese individuals.

Now Calculate Macros: Protein, Fat, & Carbs

So you’ve got your TDEE sorted. Hi Five! Now let’s figure out the macronutrient ratios that will make up your diet.

Here are the calorie values for each macronutrient:

  • 1g Protein = 4 Calories
  • 1g Carbohydrate = 4 Calories
  • 1g Fat = 9 Calories

Protein

First, let’s start with protein. Protein is essential for the growth of new tissue as well as fixing broken tissue – like what happens when you work out. Protein should be your new best friend if you want to gain or maintain muscle.

When lifting heavy and body building, some use a measure of 1 g of protein per pound of bodyweight. However, for most people a more balanced approach is to start with .825 g protein per pound.

So if our individual weighs 195lbs (88 kg), and they are doing a moderate weight training program, then their protein intake will be 161 grams.

Fat

Next, let’s calculate fat. Fat has been demonized as the reason most of us are, well, fat. But that’s simply not true.

Fats can be incredibly beneficial for hitting your body composition goals, but they also affect our hormones – too little fat in our diet can be very harmful.

After a bit of research (and again, there are a lot of opinions out there) I designate 25% of overall TDEE calories to fat. This may be adjusted, but this is the starting point.

To figure out 25% of Overall TDEE:
3,250 Calories x 0.25 ( = 812.5 Calories) divided by 9 (9 calories per gram of fat) = 90.27g Fat (which I’d round down to 90 g).

Carbohydrates

calculate macros

If there’s one thing the Flexible Dieting community of the world agrees on it’s this: We love Carbs!

Think of all your favorite foods and chances are they are high in Carbohydrates. Your body uses carbohydrates to make glucose which is the preferred fuel or energy that our bodies run off of. They’re what keeps us going.

Fiber, which is important to track if you want to be healthy, is also a carbohydrate but doesn’t deliver calories.

We’ve now sorted protein and fats, but how many carbs do we eat? We allocate the rest of our calories (originally calculated from our TDEE) to Carbohydrates.

We started with 3,250 Calories. We allocated 644 calories (161 g) to Protein, 813 calories (90 g) to Fat and we now allocate the rest, 1793 calories, to Carbohydrates.

Since 1g of Carb equals 4 calories we divide 1793 by 4 and get 448 g Carbohydrates.

Final Macros: 161 g Protein, Fat 90 g and 448 g Carbohydrates for this guy to maintain his current weight.

Utterly Confused?

Just go and use our flexible dieting calculator. The calculator allows these variables to be tweaked. We are all individuals and one formula does not suit all.

So How Do I Track My Macros?

1. Use an app

For beginners we recommend My Food Diary – it has one of the clearest and easiest food searches around.

Also popular is MyFitnessPal (iOS / Android) – see our tutorial.

2. Buy a Food Scale

A lot of nutritional information is available on food packaging, however, a scale will ensure you accurately track what you eat.

And that’s it. Do the above and you will be well on your way to getting started with Flexible Dieting. As I mentioned the above guidelines aren’t perfect. But it’s a starting place.

So get started and adjust as needed!

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    References:

  • Mifflin, M. D., St Jeor, S. T., Hill, L. A., Scott, B. J., Daugherty, S. A., & Koh, Y. O. (1990). A new predictive equation for resting energy expenditure in healthy individuals. The American Journal of Clinical Nutrition, 51 (2), 241-247. URL http://www.ajcn.org/content/51/2/241.abstract
  • Tipton, K., & Wolfe, R. R. (2001). Exercise, protein metabolism, and muscle growth.
  • Fogelholm, M., Anderssen, S., Gunnarsdottir, I., & Lahti-Koski, M. (2012). Dietary macronutrients and food consumption as determinants of long-term weight change in adult populations: a systematic literature review. Food & nutrition research, 56.

480 Comments

  1. ashley l sullivan 3 months ago

    Hi. I calculated my Macros to where I would be eating 1200 cals for protein, 675 for fat and 845 for carbs. But this is for maintenance. How would I adjust these for carb cycling for high, low, and normal carb days?

    Reply
    • Ted 2 months ago

      Hi Ashley, That’s a lot of protein! Are you sure you need that much? Your carbs should cycle according to your exercise, not some arbitrary cycle. More when you exercise less when you don’t. See here: https://healthyeater.com/carb-cycling-flexible-dieting

      Reply
      • AshleyLashun 2 months ago

        I used the calculator to determine my macros and it told me 300g of protein per day which is 1200 calories right? I just feel really lost. I need someone to explain this to me like I’m 3 years old. I understand that I should eat high carbs on the days I workout. But I’m just really confused on how to cycle my macros. Is there a formula to use to help me figure out what each one should be cut to?

        Reply
        • Ted 2 months ago

          Hi Ashley, Your question has me confused. 300g of protein? that doesn’t seem right. Cycle your macros? Not sure what you mean by that. Perhaps the best thing for you to do would be to start at the beginning and first, understand the concept of flexible dieting before you jump in to calculating your macros. Check out my book as it will take you through the process from start to finish in a basic way. https://healthyeater.com/ebook

          Reply
  2. Melissa 6 months ago

    Will the above listed calculations still work if I am calculating my protein based on my goal weight and not my current weight? Mostly everything I’m reading says that I should calculate my protein requirements based on goal weight and not current weight. My goal is to loose around 35lbs.

    Reply
    • Ted 6 months ago

      Hi Melissa, That is technically more accurate because the 1 gram per pound rule is based on lean body mass. However, we have the .825 calculation that would account for this in most cases and probably put you pretty close to your goal weight protein amount.

      Reply
  3. Alex 7 months ago

    Hi, i had a quick question. I calculated my macros both for the days I work out plus for my two rest days using the light activity and sedentary options. Right now I am trying to lose weight so I added the calorie deficit at 20%, is it better for me to do my protein calculation at .825 or 1? I also put my fats at around 22%. Thank you!

    Reply
    • Ted 7 months ago

      Hi Alex, If you’re doing any type of weight training or if you want to help preserve muscle mass than 1 gram per pound is recommended. However, if you have a lot of fat to lose this can skew the calculation. If 50+ pounds of your body weight is fat than 1 gram of protein per pound is too much and .825 is more appropriate.

      Reply
      • Alex 7 months ago

        Hi Ted, thanks so much for answering!
        Currently, those five days I do work out is weight training.

        For the light activity option, I got 154P/38F/148C with the 1:1 ration for Protein, and 127P/38F/175C with the .825.

        I was just conflicted in regards to which one would be most beneficial since the spike in difference between carbs and protein seems to be significant.

        Thanks again!

        Reply
        • Ted 7 months ago

          In that case, do the 1:1 ratio so use the first set.

          Reply
  4. Debbie Cindy 7 months ago

    Hi wanted to check. What if I’m currently still breastfeeding my child and planning to lose weight at the same time? I’ve checked from another website (specific for nursing mom) that my caloric needs should be around 1863 cal/day. I work out 3x a week as well. How much should i be needing if i want to lose weight but at the same time being able to breastfeed my baby?

    Reply
  5. AnnaLisa Elizabeth 7 months ago

    I tried to calculate the REE formula several times. I keep coming up with a severely low REE and TDEE. I have successfully used the male formula for my boyfriend. I don’t know what I’m doing wrong on my own. I am a 37 year old female. I weigh 135lb (62kg), I’m 5’5″ (65cm).
    10*62 + 6.25*65 – 5*37 – 161= 680 REE
    I work out 4-5 times a week for 30-45 min..running (4miles), vinyasa yoga, weight work incl abs, legs, upper body. I am also very busy in general. I usually count myself as moderately active.
    680*1.55= 1054 calories
    This doesn’t seem possible for me…or healthy.
    I don’t know where I’m messing this up. Can anyone else tell?
    Thanks

    Reply
    • Ted 7 months ago

      Hi Annalisa, Just a simple mistake. You have to convert your height to centimeters not inches. You’re 65 inches tall which is 161.1 cm

      Reply
      • AnnaLisa Elizabeth 7 months ago

        *palm to face. I figured I was something simple. Thank you!!!

        Reply
  6. Jenny New 8 months ago

    Hey. I was wondering if you could help me please? I have recently got into fitness. Well I’ve always been on and off but I am determined this time.

    I was having 1,200 cals and someone told me that was way too low for me. So I calculated my info. And the calculator said I should be having this. I’m 20, weigh 63.3kg and my height is 160cm and my body fat is 27.8%
    I am wanting to lose weight and build lean muscle. The results say I should be having 1881 calories. 238g C, 114g P & 52g F! Is that right? I am active I burn between 800-1200 or abit more cals 5/6 times a week. Also I was told to have 5-6 small meals a day should I do that or stay with 3? Hope you can help! Thank you.

    Reply
    • Ted 8 months ago

      Hi Jenny, Yes, you hadn’t been eating enough. You need to support your metabolism and your activity. You should divide your eating up as it best suits your hunger levels. I would really recommend getting started on the right foot by getting our flexible dieting solution. https://healthyeater.com/ebook

      Reply
      • Jenny New 8 months ago

        Thank you 😊

        Reply
  7. Jannela Harish 8 months ago

    HI i am harish i want gain muscle and loose my body fat it is around 24% .can i get any advices please?

    Reply
    • Ted 8 months ago

      Hi Harish, You would want to do the calculations outlined above factoring a 20% calorie deficit. You can also use our calculator which will do this for you.

      Reply
      • Jannela Harish 8 months ago

        HI SIR,how to get a lean body….
        workouts
        diet ,any advices please?

        Reply
  8. gabrielle 9 months ago

    Hi i am trying to work out my macros but not sure what to put my TDEE as after exercise, whether it be maintain or lose weight? I’m wanting to lose body fat but gain muscle. I paid for someone to do my macros and they came up with 1500 calories, 101g P, 150g C, 50g fat. Yet when i did your calculations and set it at maintain (as i wasnt sure what to put) i came up with 1881 calories, 92g P, 261 C, 52g F. I’m 5ft 3 female and weigh 112lbs. Can you give any advice please?

    Reply
    • Ted 9 months ago

      Hi Gabrielle, You have to be in a calorie deficit to burn fat but not too much that you won’t gain muscle. Matainance wouldn’t do this for you.

      Reply
      • gabrielle 9 months ago

        Thank you for your reply! So on your macro calculator would i use the lose weight 10% setting or the lose weight 20% one? According to my fitness tracker i burn on average 2000 calories a day and i work out 6x a week.

        Reply