How to Count Macros — and Whether You Need To
You probably do not need to count all three. Total energy decides whether your weight goes up or down, protein is the one macronutrient worth a daily target for almost everyone, and the carbohydrate-fat split matters far less for weight than the arguments about it suggest. Counting macros is still worth learning — for training, a cutting phase, a medical diet — so here is how it works, in grams, with the evidence and a worked example.
The hierarchy: energy, then protein, then everything else
Start with the largest trial of carbohydrate against fat. DIETFITS, published in JAMA in 2018, randomised 609 adults aged 18 to 50 with a BMI of 28 to 40 to a healthy low-fat or a healthy low-carbohydrate diet for twelve months. The groups ended up genuinely different — 48 percent of energy from carbohydrate versus 30, 29 percent from fat versus 45 — and lost 5.3 kg and 6.0 kg respectively. The 0.7 kg gap was not statistically significant, and neither genotype pattern nor insulin secretion predicted which diet suited whom.
Protein is the exception. A 2018 meta-analysis of 49 trials with 1,863 participants found that extra protein increased the muscle and strength people gained from resistance training, with the benefit levelling off at a total intake of about 1.6 g per kilogram of bodyweight a day. During a deficit it matters more, not less: in a four-week trial of 40 young men eating roughly 40 percent below requirements while training six days a week, the group on 2.4 g/kg gained 1.2 kg of lean mass and lost 4.8 kg of fat; the group on 1.2 g/kg gained 0.1 kg and lost 3.5 kg. Same calories, same training, different protein.
So: get the energy roughly right, get protein to a target, then decide whether the carbohydrate-fat split needs your attention at all. For most people it does not — it changes how you feel and train, a fine reason to adjust it, but not what moves the scale.
The energy part is a post of its own: how to count calories to lose weight covers the deficit size and the pace that comes before any of this.
The arithmetic behind a macro: 4, 4 and 9
A macro is a gram of something; the calorie is what that gram is worth in energy. The conversion is a convention, not a measurement of your lunch: 4 kcal per gram of protein, 4 per gram of carbohydrate, 9 per gram of fat. These are the Atwater general factors, as the FAO describes them, which every label and database uses. Alcohol carries 7 kcal per gram and belongs in the energy total, though nobody sets a target for it.
Two things stop the numbers adding up. Fibre is a carbohydrate by chemistry but is barely digested, so EU food-labelling law counts it at 2 kcal per gram rather than 4, and polyols (the sweeteners in sugar-free gum) at 2.4. And label figures are rounded per nutrient, so 4 × protein + 4 × carbohydrate + 9 × fat often lands a few percent from the printed energy value. That gap is arithmetic, not an error in your log.
The definition that catches people: what “carbohydrate” means depends on where the label was printed. Under EU rules a carbohydrate is one your body metabolises, so fibre sits on its own line, outside the carbohydrate figure. On a US Nutrition Facts panel, Total Carbohydrate is calculated by difference and fibre is listed inside it. The same bag of lentils can show 20 g in Warsaw and 28 g in Chicago, and both are correct.
Set targets in grams, not percentages
The familiar splits — 40/30/30 and its cousins — have a flaw that only shows up when you eat by them: a percentage of a small number is a small number. At 1,400 kcal, 30 percent protein is 105 g; at 2,600 kcal it is 195 g. But your protein need depends on what you weigh and whether you train, not on this month’s calories. So set protein and fat per kilogram of bodyweight, and let carbohydrate take what is left.
Protein: 1.6 to 2.2 g per kilo, higher end in a deficit
The International Society of Sports Nutrition’s position stand puts the range for exercising people at 1.4 to 2.0 g/kg a day, and 2.3 to 3.1 g/kg for resistance-trained people who are dieting. Those upper figures come from lean athletes and are expressed per kilogram of lean mass — the bodybuilding contest-prep review they draw on states them that way. If you carry a lot of body fat, multiplying by your full weight overshoots; the usual compromise is the weight you are heading toward. Our calculator uses 1.6 g/kg for maintenance, 1.8 for building muscle and 2.0 for losing weight — inside the published range, without pretending to more precision than exists.
Fat: a floor, not a target
Fat is the macro to keep above a minimum rather than aim at. The same contest-prep review recommends 15 to 30 percent of calories from fat even for people dieting to stage condition, who have every incentive to cut it. Our calculator uses 0.8 g per kilogram as the floor (56 g for a 70 kg person, about 27 percent of 1,900 kcal): dropping under it is a problem, going over by a dozen grams is not.
Carbohydrate: whatever is left
Carbohydrate has no established minimum, which is why it goes last. Take your calorie target, subtract protein × 4 and fat × 9, and divide what is left by 4. If nothing is left, the problem is the calorie target, not the carbohydrate: it is too low for your bodyweight. The exception is endurance athletes in a heavy training block, where the ISSN’s advice is to make adequate carbohydrate the priority.
A worked example
Take a 70 kg person with a 1,900 kcal daily target who is losing weight. Protein and fat are set per kilo; carbohydrate is what the budget has left.
| Macro | Grams a day | Calories | How it was set |
|---|---|---|---|
| Protein | 140 g | 560 kcal | 2.0 g per kg × 70 kg |
| Fat | 56 g | 504 kcal | 0.8 g per kg × 70 kg |
| Carbohydrate | 209 g | 836 kcal | 1,900 − 560 − 504, then ÷ 4 |
| Total | — | 1,900 kcal | the calorie target came first |
No need to do this by hand: the macro calculator takes a calorie target, a bodyweight and a goal and produces exactly this table, and if you do not have a calorie target yet the calorie calculator works one out with the Mifflin-St Jeor equation, rounded to 10 kcal because the equation’s own error is about 10 percent. Both run in your browser and store nothing. Turning the number into a daily routine is covered in our guide to counting calories — this post assumes that part is working.
Reading a label for macros
An EU label lists energy, fat, of which saturates, carbohydrate, of which sugars, protein and salt, per 100 g or 100 ml and sometimes per portion. The “of which” lines are subsets — saturates are part of the fat figure, sugars part of the carbohydrate figure — so never add them on top. Fibre, where declared, is its own line. Multiply each figure by the weight you actually ate divided by 100, and treat the manufacturer’s portion as a suggestion, not a fact.
Labels are also allowed to be off by about 20 percent in both the EU and the US, which caps anyone’s macro accuracy and is why the grams you land on are estimates. The tolerances are laid out on our accuracy page.
The mistakes that make macro counting useless
- Counting “net carbs” inconsistently. Subtract fibre from a US-style total-carbohydrate figure and then again from an EU label that never included it, and you have subtracted it twice. Pick one convention for the whole log; in Europe the simplest is to take the carbohydrate line as printed and forget net carbs.
- Guessing protein in mixed dishes. A 350 g chicken curry is not 350 g of chicken. Log the components — roughly how much meat, sauce and rice — or you will overstate protein on every restaurant meal.
- Forgetting cooking oil. A tablespoon is about 14 g of fat, roughly 125 kcal, invisible on the plate; a dressing often carries more than the salad.
- Mixing raw and cooked weights. Rice roughly triples in weight when cooked; meat loses a good share of its weight. Use the database entry that matches the state you weighed.
- Reconciling macros against calories. 4 × protein + 4 × carbohydrate + 9 × fat rarely equals the label energy exactly, for the fibre and rounding reasons above. Log the printed values and stop trying to make them agree.
- Chasing the exact number daily. Within 20 g of your protein target five days a week beats exact on Monday and abandoned by Thursday.
Who actually benefits from counting all three
Macro counting earns its overhead in a few situations. If you lift and want the training to show, protein at a per-kilo target is the whole point. In a cutting phase — dieting while trying to keep muscle — the protein figure climbs and the margin for error on the other two shrinks, which is when tracking all three starts to pay. Endurance athletes in a serious block need enough carbohydrate, and a log is the only way to know.
Some medical diets are macro diets by definition: carbohydrate counting for insulin dosing is the obvious one, and some conditions restrict protein rather than raise it. There the targets are set by your care team and nothing in this article overrides them. If you have a medical condition, are pregnant, or notice the numbers starting to run your day rather than inform it, talk to a clinician before changing anything.
Everyone else — most people trying to lose or hold weight — can stop at calories and protein. Track the energy total, land near a protein figure most days, keep fat above the floor by eating normally, and let carbohydrate be the rest. That is one and a half numbers, and it captures nearly all of the benefit.
How this works in Olivka
Disclosure: Olivka is our product. It is a free trial followed by a paid subscription, and the plan and price are shown at the end of onboarding, not here.
You send a photo, a voice note or a sentence in WhatsApp, Messenger, Telegram or Instagram and get back an itemised meal card — calories per ingredient, protein, carbohydrate and fat for the meal — matched against USDA FoodData Central and Open Food Facts, with a web lookup for restaurant and branded items. A photo of a nutrition label is read directly. A later correction — “there was cream in it” — replaces the entry rather than stacking a second meal.
You can set a daily calorie target and, separately, gram targets for protein, carbohydrate and fat — in the chat by saying so, or on the web dashboard — and the dashboard shows each as its own progress line for the day. Set only calories and protein and the other two simply show what you ate, with no percentage and no invented default. The first meals are free; nothing to install.
Frequently asked questions
Do I need to count macros to lose weight?
No. Weight change follows total energy, and the largest trial to compare a low-fat with a low-carbohydrate diet — 609 adults over twelve months — found no significant difference between them. The one macronutrient worth a daily target during weight loss is protein, because it protects muscle and keeps you fuller; in a trial of men dieting hard while training, 2.4 g per kilogram preserved and even built lean mass where 1.2 g per kilogram did not. Track calories and protein, keep fat above a minimum, and let carbohydrate be the remainder.
How many grams of protein should I eat a day?
For people who exercise, the International Society of Sports Nutrition gives 1.4 to 2.0 g per kilogram of bodyweight a day, and a 2018 meta-analysis of 49 trials found muscle gains from training stop improving beyond about 1.6 g per kilogram. While losing weight, aim toward the top of the range or a little above it — our calculator uses 2.0 g per kilogram for a weight-loss goal. If you carry a lot of body fat, multiply by the weight you are heading toward rather than your current weight, since the higher published figures were derived per kilogram of lean mass.
What is the difference between counting macros and counting calories?
Calories are the total; macros are what the total is made of. Every gram of protein and carbohydrate is counted at 4 kcal and every gram of fat at 9, so if you know the grams you know the calories, but not the other way round. Counting calories answers how much you ate. Counting macros also answers whether enough of it was protein, whether fat stayed above a floor, and how much carbohydrate was left — which matters for training, cutting phases and some medical diets, and matters much less for weight alone.
Why do the macros on a label not add up to the calories?
Two reasons, both legitimate. Fibre is chemically a carbohydrate but is barely digested, so EU labelling law counts it at 2 kcal per gram instead of 4 and lists it on its own line; polyol sweeteners are counted at 2.4. And each figure on a label is rounded separately, so 4 × protein plus 4 × carbohydrate plus 9 × fat lands a few percent away from the printed energy. On US labels the carbohydrate figure additionally includes fibre, which the EU figure does not. Log the printed values as they are and do not try to reconcile them.