The Best Way to Calculate Your Macros

by DeanMcKillop 1958 views Nutrition

The Best Way to Calculate Your Macros

MOOOOOORRRREEE PROTEIN… that’s usually the answer people give when looking to change their body composition. But how much protein do you really need and what about carbohydrates, fats and fibre too? It’s time to break out the popcorn and grab a calculator as we delve into how many grams of each macronutrient you really need.

So where do we start?

Before determining your daily macronutrients, the first thing you need to consider is your goal.

  • Do you want to build muscle?
  • Do you want to lose fat?
  • Do you want to enhance performance?

It is those 3 factors that first determine your caloric intake, which you can then use to determine your macronutrients.

Build Muscle – Multiply your body weight by 37- 44 for a calorie surplus

Lose Fat – Multiply your bodyweight by 26-31 for a calorie deficit

Enhance Performance – Multiply your bodyweight by 32-44 for either caloric maintenance or a caloric surplus, depending on your body weight goals.

First step done…Now, on to the next step.

I personally like to allocate numbers to the essential macronutrients first, as they have primary dietary importance and then the remaining calories are given to the non-essential stuff that our bodies can otherwise make themselves if need be.


Take your lean body mass (everything other than fat) and multiply it by 1.5-2.5g per kg.

Yes, I know it's a fairly significant range, however, this range will theoretically cover almost all bases of muscle gain, muscle recovery and muscle retention in all 3 phases of dieting (deficit/maintenance/surplus).

Within this range, the following variables may be worth considering.

  • Women traditionally need less protein than men
  • Eating in a caloric surplus requires less protein for recovery
  • Eating in a caloric deficit requires more protein for muscle loss prevention
  • Increased resistance stress may require more protein for recovery
  • Protein is the most satiating macronutrient of the 3 available to blunt hunger

Taking these factors into consideration will then allow you create more specificity in your protein requirements.

Note – One (1) gram of protein contains 4kcal


You have two approaches you can use when determining how many grams of high-quality fats you should be consuming per day. The simplest approach, however, is to take 20-30% of your total calories and allocate that amount to fat intake.

Within this range, the following variables may be worth considering.

  • Women traditionally respond better to a higher fat percentage for menstrual regularity
  • The lower the calories go, the higher the importance of fats become for hormonal support
  • During phases of excess caloric surpluses, a lower fat percentage can be maintained when compared to deficit dieting
  • High-intensity output athletes require more carbohydrates for energy, which defaults fat percentages to be lower than those who are sedentary

Taking these factors into consideration will then allow you create more specificity in your fat requirements.

Note – One (1) gram of fat contains 9kcal


Carbohydrates, from a physiological point of view, are by virtue considered to be a non-essential nutrient. This means our body can break down other tissues and create carbohydrate-based energy during times of need. Despite this, carbohydrates play vital roles in energy production, metabolic regulation, brain function, gastrointestinal health and they are also the most muscle sparing macronutrient available.

To obtain the level of carbohydrates you require, find the remaining calories you have left over from your allocations to protein and fats and allocate them to carbohydrates.

For practical purposes, the below example is how you would do this based on a person who is 85kg with 70kg lean mass in a caloric deficit.

  • Calories – 28x85 = 2380kcal
  • Protein – 2.5x70 = 175g (700kcal)
  • Fats – 0.25x2380 = 595kcal (66g)
  • Carbs – 2380-700-595 = 1085kcal (271g)

Simple right? Yes, it really is simple… but what else do we need to consider?

Remember, these numbers you are setting are simply a baseline that will allow you to test and measure how you are feeling physically and psychologically. Once you have determined your baseline calories, taking data on the following aspects will allow you to then make educated decisions on what macronutrient changes may enhance your approach.

  • How are you recovering?
  • How is your hunger?
  • How is your energy?
  • How is your sleep?
  • Do you have any gastric stress?
  • If female, has your cycle changed and if so what is your total systemic stress levels like?
  • Can you follow these macronutrients consistently?
  • Are you performing better each week or are you losing strength?
  • Do you notice you feel better/worse eating carbohydrates or fats?
  • How extreme do you want to change your body composition?

protein carbohydrates fats

And the list goes on…

All of those factors should be considered important feedback that you can use to determine whether or not your diet is successful.

While it would be nice to have a 1 size fits all approach to setting macronutrients, the reality is that we are an adaptive organism that requires careful consideration for optimal performance. Your greatest asset in the world of manipulating your body is your ability to individualise your approach and tailor it to your own personal needs but also to test, measure and record data on how you respond to changes.

Still uncertain what macronutrients are best for you?

All you have to do is choose a starting point, test it, measure it, and then adapt it accordingly.

Outside of that… have fun with it and embrace the satisfaction of having complete control over how you look and feel instead of relying on someone else to tell you what to eat and what to do.


Article updated by Paula Vargas Duran for Fit Talk.


Exercise Scientist

I completed my Exercise Science Degree at the University of QLD and have worked in the fitness industry for over 8 years, including a short stint at the Brisbane Broncos in 2010 as a student. I also hold my Level 2 Strength and Conditioning Coach accreditation (ASCA) and have competed in 1 bodybuilding season, placing 2nd at the IFBB u85kg Nationals.

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