Macros explained: protein, carbs, fat and how to set your gram targets

Calories tell you how much energy you eat; macros tell you where it comes from. If you already count calories, gram targets turn one number into a clearer plan for each meal.

If you have diabetes, kidney disease or another medical condition, take medication, are pregnant or breastfeeding, or have a history of disordered eating, talk to your doctor or a registered dietitian before you change your macros.

What are macros?

Macronutrients are the nutrients you eat by the gram, and they supply almost all of the energy in food. WHO describes their roles:

• Protein provides the building blocks for muscle and other tissues, hormones and enzymes (meat, fish, eggs, dairy, legumes, tofu).
• Carbohydrate is the body’s primary energy source (grains, potatoes, fruit, vegetables, pulses, milk).
• Fat is essential: two fatty acids, linoleic and alpha-linolenic acid, can only come from your diet (oils, nuts, seeds, avocado, fish).

Fiber is carbohydrate that isn’t digested or absorbed in the small intestine, so it provides less energy. Alcohol provides energy too, but it isn’t a nutrient you need.

How many calories per gram of protein, carbs and fat?

Labels and apps calculate energy with standard conversion factors. EU food law lists them in Annex XIV of Regulation (EU) No 1169/2011, and US labeling rules use the same general factors of 4, 4 and 9 calories per gram for protein, carbohydrate and fat.

Gram for gram, fat carries more than twice the energy of protein or carbohydrate. That is why a spoonful of oil changes a meal far more than a spoonful of rice, and why fats top the list of hidden calories most people miss. Alcohol, at 7 kcal per gram, counts toward your calories but not toward protein, carbohydrate or fat, so on days you drink, your macro grams add up to fewer calories than your total.

Fiber, net carbs and labels

On US labels, total carbohydrate is calculated by difference – the food’s weight minus its protein, fat, water and ash – so it includes fiber. EU rules count fiber separately from carbohydrate, at 2 kcal per gram. So if you track “net carbs”, subtract fiber only from a US-style total. Our guide on how to read a nutrition label covers the other differences.

How much protein, carbs and fat should you eat?

Health authorities set macro ranges as a share of daily energy, and the ranges are deliberately wide.

For carbohydrate and fat, the ranges overlap at roughly 45–60% carbohydrate and 20–30% fat. WHO is stricter on fat and adds limits for trans fat (no more than 1%) and free sugars. Its protein figure is what is generally enough, not a ceiling: WHO notes that athletes and people building or maintaining muscle may eat more than 15%.

Protein is also set per kilogram of body weight. The US and Canadian Recommended Dietary Allowance for adults is 0.8 g per kg a day, about 56 g if you weigh 70 kg (154 lb). Our guide to how much protein you need per day explains when more makes sense.

How to calculate your macros: a worked example

Say your calorie target is 2,000 kcal a day. This is only an example; to set your own, see our guide to calorie deficits and plateaus.

1. Pick percentages that add up to 100. Here: 20% protein, 50% carbohydrate and 30% fat, inside the US, EU and WHO ranges.
2. Convert to calories. Multiply 2,000 kcal by each share: 400 kcal protein, 1,000 kcal carbohydrate, 600 kcal fat.
3. Convert to grams. Divide by 4 for protein and carbohydrate and by 9 for fat: 100 g, 250 g and about 67 g.
4. Check the total. 100 × 4 + 250 × 4 + 67 × 9 = 2,003 kcal. Small rounding differences are normal.
5. Add a fiber target. US and Canadian fiber values are based on 14 g per 1,000 kcal, which gives 28 g here. EFSA considers 25 g a day adequate for adults, and WHO recommends at least 25 g.

At 70 kg (154 lb), 100 g of protein is about 1.4 g per kg, or roughly 25 g at each of three meals and a snack.

Higher protein or lower carb: adjusting the split

With your calorie target fixed, moving energy between macros changes what your meals look like, not the total:

Higher protein

Protein at 25–30% of energy stays well inside the US and Canadian range of 10–35%. Take the extra energy mainly from carbohydrate and keep fat at 20% or more, the lower end of the US and EU ranges. WHO cautions that excessive protein can burden the body, particularly the kidneys, so if you have kidney disease, ask your doctor first.

Lower carb

This split puts carbohydrate at 35%, below every reference range, and fat at 35%, above WHO’s 30%. WHO notes that low and very low carbohydrate diets are used to treat certain conditions, but that for most people unrefined carbohydrates should be a significant part of the diet. A moderate option is to stay near 45% and choose high-fiber sources. If you have diabetes or take medication that lowers blood sugar, talk to your doctor before you cut carbohydrate significantly.

Why food quality matters as much as the numbers

Two days can hit identical macro targets with very different food: 250 g of carbohydrate from oats, lentils and fruit brings far more fiber than the same grams from white bread and soft drinks. WHO’s advice focuses on where your macros come from:

• Carbohydrate: mainly whole grains (such as oats, millet, maize, wheat and brown rice), vegetables, fruit and pulses, with at least 400 g of fruit and vegetables a day.
• Free sugars (sugars added to food and drinks, plus those in honey, syrups and fruit juice): less than 10% of energy – about 50 g, or 12 level teaspoons, on 2,000 kcal – and ideally 5% or less.
• Fat: prefer unsaturated fats (fish, avocado, nuts, and olive, sunflower or canola oil) over saturated ones (fatty meat, butter, palm and coconut oil, cheese, ghee). Keep saturated fat to no more than 10% of energy, about 22 g on 2,000 kcal.
• Protein: a mix of plant and animal sources.

EFSA’s advice for Europe points the same way: limit saturated and trans fats and replace them with mono- and polyunsaturated fats.

Common macro-tracking mistakes

• Using 4 kcal for fat. Fat is 9 kcal per gram, so a 67 g fat target is 600 kcal, not 270.
• Chasing exact grams every day. Being close on most days and on target as a weekly average is a realistic goal.
• Keeping percentages when your target changes. On 1,800 kcal, 20% protein is 90 g instead of 100 g. To keep protein steady, set it in grams first and split the remaining calories between carbohydrate and fat.
• Judging food by macros alone. A “high-protein” bar can still be high in sugar and saturated fat, so read the whole label.

If tracking grams starts to feel stressful, step back to tracking calories or simply building balanced plates, and talk to a professional if it affects your wellbeing.

How Portiva helps

Portiva sets calorie and macro targets and adapts them to your weight trend and logs, with a plain-words explanation of each change. You can log meals by photo, live camera scan, voice or text. When something would change the numbers a lot, such as oil, butter or a sauce, Portiva asks one short question instead of guessing, and you can edit any item before saving. It also scans barcodes and reads nutrition labels from a photo.

Frequently asked questions

How do I calculate my macros?

Start with a daily calorie target, choose percentages for protein, carbohydrate and fat that add up to 100, and multiply your target by each one. Divide the protein and carbohydrate calories by 4 and the fat calories by 9 to get grams. For example, 20% protein on 2,000 kcal is 400 kcal, or 100 g. Recalculate whenever your calorie target changes.

What is the best macro ratio for weight loss?

There is no single best ratio. Your calorie intake over weeks has the biggest effect on your weight, while the split shapes your meals. Within the reference ranges, choose a split you can keep, with enough protein, plenty of fiber and fat at 20% of energy or more. If you have a medical condition, ask your doctor or a registered dietitian.

How many calories are in a gram of protein, carbs and fat?

Protein and carbohydrate provide about 4 kcal (17 kJ) per gram and fat about 9 kcal (37 kJ). Alcohol provides about 7 kcal (29 kJ) per gram and fiber about 2 kcal (8 kJ). These are the EU labeling factors, and US labels use the same 4, 4 and 9 for the three macros.

Should I count net carbs or total carbs?

Either works if you are consistent and know which one your label shows. On US labels, total carbohydrate includes fiber, so net carbs means total minus fiber. EU-style labels list carbohydrate without fiber already, so don’t subtract it again. For most people, total carbohydrate plus a separate fiber target is the simplest approach.

Sources

1. Regulation (EU) No 1169/2011, Annex XIV: Conversion factors, The National Archives, legislation.gov.uk (2011).
2. 21 CFR 101.9 – Nutrition labeling of food, U.S. Government Publishing Office (2025).
3. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids, National Academies of Sciences, Engineering, and Medicine (2005).
4. Dietary reference intakes tables: Reference values for macronutrients, Health Canada (2025).
5. EFSA sets European dietary reference values for nutrient intakes, European Food Safety Authority (2010).
6. Healthy diet, World Health Organization (2026).