Macronutrients: What Are They and How Do You Calculate Your Macros?

By Roel van den Bogaard, personal trainer at Aurora Personal Training in Eindhoven.

Macronutrients are protein, fats and carbohydrates: nutrients your body uses in relatively large amounts. They provide energy and each has its own functions. Protein supports tissue maintenance and repair, carbohydrates provide fuel, and fats supply essential fatty acids, among other roles.

Whether you want to get stronger, lose weight or understand your food better, knowing these three nutrients helps. You do not need to calculate every meal to the nearest gram. Start with the basics and use numbers as a tool when you want more insight.

Macronutrients are often shortened to “macros”. These are their main differences:

These energy values apply to protein, fat and digestible carbohydrates. Foods usually contain several macronutrients. Pulses provide both protein and carbohydrates, for example, while nuts contain fat and protein.

Macronutrients are the protein, fats and carbohydrates in your diet. Micronutrients are vitamins and minerals. You need smaller amounts of these, but they are important too. Vitamins and minerals do not provide calories.

A macro split therefore does not tell you everything about the quality of your diet. Variety, fibre, vitamins and minerals also deserve attention. Reaching your protein target alone does not make an eating pattern nutritionally complete.

Protein provides amino acids your body uses to build and maintain tissues. People training specifically for muscle growth may need more protein than those without that training goal.

For healthy adults, the general recommended intake is approximately 0.83 grams per kilogram of body weight per day. For people doing substantial strength training to build muscle, the Netherlands Nutrition Centre gives a range of 1.2–2 grams per kilogram per day, depending on the goal.

These are general reference values. Your individual needs also depend on your circumstances and eating pattern. More protein is not automatically better.

Start practically: identify the protein source in your breakfast, lunch and dinner. Options include quark, eggs, tofu, beans, lentils and fish.

A protein shake can be convenient, but it is unnecessary if ordinary food already provides enough.

Carbohydrates provide energy. Your body can store glucose as glycogen in your muscles and liver, making fuel available for exercise.

Regularly choose whole grains, potatoes, fruit, vegetables and pulses. These choices also contribute fibre and other nutrients.

The distinction “simple carbohydrates are bad, complex carbohydrates are good” is too simplistic. White bread, for example, mainly contains starch, a complex carbohydrate. That does not automatically make it a high-fibre choice.

A food’s structure, preparation and the rest of the meal influence how it is digested.

You do not need to automatically remove bread, pasta or rice when trying to lose weight. Consider your overall eating pattern and portions that suit your needs.

Fats provide energy and essential fatty acids. They also play a role in the absorption of fat-soluble vitamins.

Because fat provides 9 kcal per gram, even small portions can make a meaningful contribution to your energy intake.

Often choose sources of unsaturated fats, such as olive oil, unsalted nuts, avocado and oily fish. Butter contains a substantial amount of saturated fat and should therefore not lead a list of preferred fat sources.

You can use regular olive oil for frying and cooking. Avoid heating it until it smokes. The claim that olive oil can only be used cold is incorrect.

The Dutch reference range for total fat intake in adults is 20–40% of daily energy intake. This is a range, rather than a compulsory fixed ratio for everyone who trains.

Calculate a macro split from an estimated daily calorie intake. Then decide how much protein and fat fits that intake and calculate the remaining amount available for carbohydrates.

Step 1: establish your calorie starting point

Your energy needs depend on factors including body size, age and activity.

A calculator provides an estimate. Use your weight trend over several weeks to assess whether that estimate matches your circumstances.

Weight loss requires an energy deficit over time. For weight maintenance, you are looking for approximate balance between intake and expenditure. A macro split only makes sense within that overall context.

Step 2: calculate protein

Multiply your body weight by a protein target appropriate for your situation.

Example: 80 kg × 1.8 grams = 144 grams of protein per day.

Here, 1.8 grams is a chosen example for someone who strength trains. It is not a universal requirement.

Step 3: calculate fat

Suppose this example uses 2,400 kcal per day, with 30% allocated to fat:

2,400 × 0.30 = 720 kcal from fat.

720 ÷ 9 = 80 grams of fat.

Step 4: calculate the remaining carbohydrates

The 144 grams of protein provide 576 kcal. Combined with the 720 kcal from fat, this totals 1,296 kcal.

2,400 − 1,296 = 1,104 kcal available for carbohydrates.

1,104 ÷ 4 = 276 grams of carbohydrates.

Worked example: 80 kg and 2,400 kcal

This is a hypothetical calculation. Weighing 80 kg does not automatically mean you need 2,400 kcal. The chosen percentages are not a universally optimal split either. The example demonstrates how to convert calories into grams.

Food-label energy totals may differ slightly from calculations using these three macronutrients alone, for example because of fibre and rounding.

If you want to lose weight

Choose an eating pattern that makes an energy deficit manageable while providing sufficient protein and a varied selection of foods. Continue paying attention to strength training if maintaining muscle is a priority.

You do not need a fixed ratio such as 40/30/30. Your distribution should fit your preferences, training and daily life.

Use hunger, practicality and your progress to assess whether the approach is working.

Read more about cardio or strength training for weight loss.

If you want to build muscle

Combine appropriate nutrition with a training programme that allows you to progress. Establish your protein intake, then assess whether you eat enough energy to support your training.

Automatically prescribing an extra 300–500 kcal for everyone is too broad. A larger surplus does not necessarily produce more muscle growth.

A small study in trained participants found that faster weight gain was primarily associated with larger increases in skinfold thickness. This reinforces the value of an appropriate energy intake, but does not establish an exact ideal for everyone.

Read our guide to nutrition and muscle growth.

A calculation becomes useful when you can turn it into meals. These combinations illustrate how:

Portion sizes determine the final macros. These examples are therefore not a calculated 2,400-kcal meal plan.

Want to calculate more accurately? Use the nutrition information for the product you actually eat.

For example, if a label states 10 grams of protein per 100 grams, a 250-gram portion provides 25 grams of protein.

Also check which entry you select in a food-tracking app. A quantity of dry rice is not interchangeable with the same weight of cooked rice.

Cooking oil, sauces and toppings also belong in the calculation when you want to estimate total intake.

No. A short food diary can help you recognise patterns:

• Does your lunch contain a protein source?
• How large are your portions?
• What do you eat between meals?

Use that information to choose a few manageable improvements. You might plan a regular lunch for busy working days, keep wholegrain foods available or decide on evening meals in advance.

If tracking becomes burdensome, use familiar meals and suitable portions instead. Your approach needs to remain useful in the life you actually lead.

Are calories and macros the same thing?

No. Calories express an amount of energy. Macros are nutrients that provide energy.

For example, 10 grams of fat provide approximately 90 kcal, while 10 grams of protein provide approximately 40 kcal.

Are percentages or grams more useful?

Grams are practical when using portions and food labels. Percentages show how your total energy intake is distributed.

For protein, an amount per kilogram of body weight provides more context than a percentage alone.

Should your macros change on rest days?

A separate plan is not automatically necessary. You can start with a simple routine you can maintain.

If your activity varies considerably between days, adjusting portions may be useful. Sufficient nutrition still matters on rest days.

Is a macro calculation enough for a personal nutrition plan?

No. A calculation does not automatically account for medical circumstances, food preferences or diet quality.

If you have a medical condition or follow a medical diet, ask a dietitian to tailor your nutrition plan.

Do you understand what protein, fats and carbohydrates do, but find it difficult to apply that knowledge?

At Aurora Personal Training in Eindhoven, we connect nutrition with your training goals and daily routine.

We can discuss how to include sufficient protein in meals, which eating opportunities fit your workday and how to assess progress. This turns information into choices you can repeat.

Book a free intake at Aurora Personal Training to discuss an approach that suits you.