To set your macros for muscle gain, work in this order: calories first (maintenance + about 10 %), then protein at 1.6–2.2 g per kg, fat at about 0.7–1 g per kg, and carbs for everything that’s left. For a 75 kg (165 lb) lifter eating 2,850 kcal, that’s roughly 150 g protein, 70 g fat and 400 g carbs. The same method works for fat loss; you just start from a lower calorie number and push protein higher.
What macros are, quickly
Macronutrients are the three nutrients that provide calories:
| Macro | kcal per gram | Main job for lifters |
|---|---|---|
| Protein | 4 | Building and repairing muscle |
| Carbohydrate | 4 | Fuel for hard training, glycogen |
| Fat | 9 | Hormones, cell health, absorbing some vitamins |
Alcohol also provides calories (7 kcal per gram) but isn’t a nutrient you need.
Step 1: set your calories
Calories come first because they determine your direction.
- Estimate maintenance: roughly bodyweight in kg × 30–35 for a moderately active lifter, or use a calculator. Better: track food and weight for two weeks and see what keeps your weekly average flat.
- Choose a goal:
| Goal | Calories |
|---|---|
| Lean bulk | Maintenance + 10 % (Iraki et al. 2019 suggest 10–20 %) |
| Recomposition | Maintenance to −10 % |
| Fat loss | Maintenance − 15 to 25 % |
More on each: how to bulk, body recomposition, and how to cut.
Step 2: set protein
Protein is the only macro with a clear minimum for muscle. A meta-analysis by Morton and colleagues (2018) found muscle gains levelled off around 1.6 g per kg per day on average, with 2.2 g/kg as a safe upper target.
- Bulking: 1.6–2 g/kg (a surplus already spares protein).
- Maintenance or recomp: 1.8–2.2 g/kg.
- Cutting: 2–2.4 g/kg. In their review on contest prep, Helms, Aragon and Fitschen (2014) recommended 2.3–3.1 g per kg of lean mass when dieting, which works out around this range for most lifters.
Details in how much protein to build muscle.
Step 3: set fat
Fat supports hormone production and makes food enjoyable. Going too low for long periods isn’t a good idea.
- Typical: 0.7–1 g per kg, or about 20–30 % of calories.
- Minimum during a cut: around 0.5–0.6 g/kg.
- If you prefer fattier foods: go higher and reduce carbs accordingly.
Step 4: carbs fill the rest
Subtract protein and fat calories from your total, divide by 4. Carbs fuel your training, especially sessions with lots of sets, and most lifters perform better with plenty of them during a bulk.
Worked example: a lean bulk
Alex: 75 kg, trains four times a week, maintenance verified at 2,600 kcal.
- Calories: 2,600 × 1.10 = 2,860 kcal (round to 2,850).
- Protein: 75 × 2.0 = 150 g → 600 kcal.
- Fat: 75 × 0.9 = ~68 g → about 610 kcal. Round to 70 g → 630 kcal.
- Carbs: 2,850 − 600 − 630 = 1,620 kcal ÷ 4 = 405 g.
| Macro | Grams | kcal | Share |
|---|---|---|---|
| Protein | 150 g | 600 | 21 % |
| Fat | 70 g | 630 | 22 % |
| Carbs | 405 g | 1,620 | 57 % |
| Total | 2,850 |
Worked example: a cut
Sam: 68 kg, maintenance 2,200 kcal, wants to lose about 0.5 kg a week.
- Calories: 2,200 − 450 = 1,750 kcal.
- Protein: 68 × 2.2 = 150 g → 600 kcal.
- Fat: 68 × 0.7 = 48 g → 430 kcal (round to 50 g / 450 kcal).
- Carbs: 1,750 − 600 − 450 = 700 kcal ÷ 4 = 175 g.
Protein is the same number of grams as Alex’s despite fewer calories, because it matters more during a deficit.
Turning macros into meals
You don’t need to plan every gram. A simple template for Alex’s bulk:
| Meal | Example | Protein / Carbs / Fat |
|---|---|---|
| Breakfast | 100 g oats, 300 ml milk, banana, 1 scoop whey | 45 / 100 / 12 |
| Lunch | 150 g chicken, 100 g rice (dry), vegetables, 1 tbsp olive oil | 50 / 85 / 18 |
| Snack | 200 g Greek yoghurt, granola, honey | 20 / 60 / 8 |
| Dinner | 150 g lean beef, 400 g potatoes, salad, 30 g cheese | 45 / 75 / 25 |
| Evening | 2 slices toast, peanut butter | 10 / 40 / 12 |
| Total | ~170 / 360 / 75 |
Close enough. Protein is a bit higher, carbs a bit lower; that’s fine. For protein-dense ingredients, see our list of high-protein foods.
How to adjust over time
Macros are a starting point, not a prescription. Check every two weeks:
| What you see | Change |
|---|---|
| Weight moving at target rate | Nothing |
| Bulk: gaining too fast | Remove 25–40 g carbs (100–150 kcal) |
| Bulk: not gaining | Add 25–40 g carbs |
| Cut: not losing | Remove 25–40 g carbs or 10–15 g fat |
| Cut: losing fast, strength dropping | Add 25–40 g carbs |
Protein stays put. Calories move through carbs and fat.
Your training numbers are the other half of the check. On a bulk, your lifts should climb; on a cut, they should hold. Brick shows last session’s weights and reps on every set and draws an estimated 1RM trend for each exercise, so you can match your nutrition changes against real performance.
Do you need to track macros forever?
No. Tracking for a few weeks teaches you portion sizes and where protein comes from. After that, many people switch to simpler rules: a protein portion at every meal, carbs scaled to activity, fats from whole foods, and the scale checked weekly. Go back to tracking if progress stalls.
Common macro mistakes
- Using percentages for protein. “30 % protein” can mean 90 g or 220 g depending on calories.
- Cutting fat too low for months. Hormones and mood can suffer.
- Fearing carbs. They’re your training fuel, especially on a bulk.
- Ignoring calories while obsessing over macros. Calories decide the direction.
- Changing too much at once. Adjust by 100–150 kcal and wait two weeks.
Frequently asked questions
What is the best macro ratio for building muscle?
There isn't a single best ratio. Set protein in grams per kg (1.6–2.2), fat at roughly 0.7–1 g per kg, and fill the rest with carbs. That often lands somewhere near 25–30 % protein, 25 % fat and 45–50 % carbs, but the grams matter more than the percentages.
Do I have to hit my macros exactly every day?
No. Being within about 10 g of protein and 100–150 kcal of your calorie target most days is plenty. Weekly consistency matters far more than daily perfection.
Is a low-carb diet bad for building muscle?
You can build muscle on low carb if calories and protein are adequate, but most lifters train better with more carbs, especially with higher-volume programs. If you prefer fewer carbs, keep at least enough to fuel your sessions and watch your performance.
Should my macros be different on rest days?
They can be, but it's not necessary. Some people eat a few more carbs on training days and fewer on rest days with the same weekly total. Keep protein the same every day.
Sources
- Iraki J, Fitschen P, Espinar S, Helms E (2019). Nutrition recommendations for bodybuilders in the off-season: a narrative review. Sports
- Helms ER, Aragon AA, Fitschen PJ (2014). Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition
- Morton RW, Murphy KT, McKellar SR, et al., Phillips SM (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine
