How to count macros: a beginner’s guide

What are macros?

Macronutrients are the nutrients your body needs in large amounts, and they are where the calories in food come from:

Alcohol is sometimes called the fourth macro: it has 7 kcal per gram but no nutritional value. Fibre counts as a carbohydrate on UK labels and provides about 2 kcal per gram.

Because every calorie comes from a macro, you can work out the calories in any food from its macros. A food with 20 g protein, 30 g carbs and 10 g fat has (20 × 4) + (30 × 4) + (10 × 9) = 290 kcal.

How to calculate your macros

1. Set your calories

Start with your maintenance calories, then subtract 300 to 600 kcal to lose weight or add 200 to 300 to build muscle. Our calorie and macro calculator does this and the next three steps for you.

2. Set protein first

Protein is the macro that matters most. Aim for 1.6 to 2.2 g per kg of body weight if you are training or losing weight. For a 75 kg person, 1.8 g per kg is 135 g of protein, which is 540 kcal. Read more in how much protein do I need.

3. Set fat

Fat should be around 25 to 35% of your calories, and not much lower than 0.6 g per kg of body weight. On 1,800 kcal, 28% is about 500 kcal, or 56 g of fat.

4. Fill the rest with carbs

Whatever is left goes to carbohydrates. In our example: 1,800 − 540 (protein) − 500 (fat) = 760 kcal, which is 190 g of carbs.

Macro splits for different goals

• Fat loss: high protein (1.8–2.2 g/kg), moderate fat, carbs to fill. Protein protects muscle and curbs hunger.
• Muscle gain: protein around 1.6–2 g/kg, a small calorie surplus, and plenty of carbs to fuel training.
• Endurance sport: higher carbs, often 5 g/kg or more on heavy training days, with protein around 1.2–1.6 g/kg.
• Low carb: works if you prefer it, but it is not better for fat loss than any other split at the same calories and protein.

How to track macros day to day

1. Use an app. Working macros out by hand is not realistic. A macro tracker app adds them up as you log.
2. Log as you eat, not at the end of the day, when meals are easy to forget.
3. Hit protein, then calories. If you get those two right most days, carbs and fat will sort themselves out.
4. Plan the first meal. A high-protein breakfast makes the rest of the day much easier. See our high protein meals.
5. Look at weekly averages. One high-carb day or a meal out doesn't matter if the week is on target.

Reading UK food labels

UK nutrition labels list energy (in kJ and kcal), fat, saturates, carbohydrate, sugars, fibre, protein and salt, per 100 g and often per portion. For macros you need the kcal, protein, carbohydrate and fat lines. Watch out for portion sizes: the “per portion” column is the manufacturer's idea of a portion, which may not be what you eat.

The traffic light labels on the front of packs use reference intakes based on an average adult eating 2,000 kcal: 70 g fat, 20 g saturates, 260 g carbohydrate, 90 g total sugars, 50 g protein and 6 g salt. Your own targets will be different, which is why personal macro targets are more useful.

The best app for tracking macros

The reason most people stop counting macros is the time it takes to log meals. Calori is a macro tracker that works from a photo: snap your plate and it logs the calories, protein, carbs and fat for you. Your macros fill up as rings on your Home Screen and Apple Watch, so you always know what is left. It is the simplest way to see whether your new macro targets are working.