How To Calculate Macros For Fat Loss


What are macros and how do you calculate macros for fat loss and cutting?

Below i will teach you how to work out your own calorie and macronutrient targets.

If you’re trying to lose weight, then there’s a good chance that you’ve heard the term ‘macros’ being used.

‘How can I calculate my macros for flexible dieting?’

‘What are your macros?’

‘Does this fit my macros?’



Macros is simply short for macronutrients. As the name ‘macro’ suggests, we require these food groups in large amounts in the diet. There are four macronutrients: protein, fat and carbohydrates and the fourth is alcohol, but we’re going to focus on the first three. So far, so good?

How many calories someone consumes per day depends on their macronutrient intake. Protein and carbohydrates have 4 calories per gram whereas fat, which is more energy dense, has 9 calories per gram.

Let’s work through an example. Say you look at a food label that has 10g of protein, 10g of carbohydrates and 5g of fat.

To work out how many calories are in that food we multiply the grams of protein (10g) by 4 + grams of carbohydrates (10g) by 4 + grams of fat (5) by 9 = 125 calories.

Here’s the deal.

There are also ‘micros’, short for micronutrients. Micronutrients include vitamins, several fatty acids and a number of inorganic elements. We need these in smaller quantities but they are essential for growth, repair and maintaining our cells.




Before you can get down to the specifics of working out what macros you need to start flexible dieting (that`s where you pick and track your own foods to hit your macronutrient targets), you need to first calculate your calorie target.

It’s important to remember that regardless of what approach you take, your calorie target is an estimation, not an exact number.

Anyway, there are several ways you can estimate how many calories you need to lose fat. We’re going to do it using a slightly more advanced way rather than simply multiplying your body weight by a number like some people may do.

Before We Can Start, I’d like You To Meet Jimmy

Jimmy is going to be our guinea pig, he wants us to be his flexible dieting coach so we’re going to work out his macros.

He’s a 30 year old male, weighing 80kg at 180cm and he hits the gym a couple of times per week. He has a desk job and he wants to know his macros for fat loss.

First off, we need to work our Jimmy’s calorie requirements.

We’ll use the Mifflin-St Jeor formula to estimate his Basal Metabolic Rate (BMR). This is essentially the amount of energy expended per day before we add in his activity levels.

There are several equations we can use but a study by the ADA (American Dietetic Association) found the Mifflin-St Jeor method to be pretty accurate. Here it is:

Men: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) + 5

Women: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) – 161.

So for Jimmy, our 30 year old male, weighing 80kg at 180cm. His BMR would roughly be: (10 x 80)+(6.25 x 180) – (5 x 30) + 5 = 1780.


Now Add Your Physical Activity Ratio

Now that we’ve worked out his BMR, we need to multiply it by a Physical Activity Ratio (the estimated cost of activity he does per day).

If you were working this out, you would need to multiply your BMR by:

1.2 if you do little or no exercise

1.4 if you do exercise a couple of times per week

1.5 to 1.7 if you exercise several times per week

1.9+ if you exercise every day or have a hard, physical job

Back to our example.

Jimmy trains a couple of times per week so we’ll multiply his BMR (1780) by 1.4. This gives us his estimated TDEE (Total Daily Energy Expenditure): 2492.

In order to lose fat, Jimmy needs to create a calorie deficit.

This means he needs to consume less calories than he needs per day in order to lose fat.

A 15% deficit is often a good place to start. With our clients, we may go higher or lower depending on their starting body fat levels, their goals and energy requirements.

Anyway, Jimmy’s calorie target to lose fat would be: 2118 calories.

All cool?

Now we know how many calories to aim for, let’s calculate some macros for cutting.




We’ll start with protein. A higher protein diet can be a great tool for fat loss. It helps preserve muscle tissue and it helps to keep you feeling full.

A good figure to aim for – when flexible deiting – is often around 2g per kg of bodyweight.

For 80 kg Jimmy, that would be around 160g of protein.

Struggling to hit your protein target? This is our favourite whey protein shake (apple cinnamon swirl flavour, soooo good!)




So far we’ve worked out Jimmy’s total calorie target: 2118 calories.

His protein target is 160g

And his fat target is 80g

That means we now need to calculate his carbohydrate requirements.

To do this, we’ll first work out how many calories we’ve assigned already. Remember how to do this?

4 calories per gram of protein and 9 calories per gram of fat, right?

That means Jimmy has been assigned 1360 kcal so far (160×4)+(80×9).

If we subtract 1360 from his calorie target (2118) he is left with 758 kcal remaining for carbohydrates.

Divide this number by 4 (because there are 4 kcal per g of carbohydrate) then his carb target is 190g.


There you have it. Jimmy’s daily macros to lose fat would be:

2118 kcal = 160g protein, 80g fat and 214g carbohydrate.




How much fat should you eat to lose fat largely depends on preference.

While the name “fat” might strike fear into the hearts of dieters across the land, you need a certain amount of fat in your diet to stay healthy.

Fat has a host of important functions in the body. Fats are essential for cell growth, repair, brain function and a host of other essential bodily functions!

Aiming for a fat intake between 0.7g – 1.2g per kg of bodyweight might be a good start.

On Jimmy’s flexible dieting plan, he is going to aim for around 1g per kg so that would be 80 g of fat for him.


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