Macro Calculator
Calculate your ideal daily protein, carb, and fat targets in grams, based on your calorie needs and goal.
Quick summary: Macros (macronutrients) are protein, carbohydrate, and fat — the three sources of dietary calories. This calculator sets protein first (based on body weight and goal, ~1.6–2.2 g/kg for muscle-focused goals), fat at a healthy minimum, and fills the remaining calories with carbohydrate.
What "macros" means
Macronutrients are the three nutrient categories that supply calories: protein (4 kcal/g), carbohydrate (4 kcal/g), and fat (9 kcal/g). "Counting macros" means hitting daily gram targets for each, rather than tracking calories alone — it adds a layer of nutritional detail that supports specific goals like muscle retention during a cut, or adequate energy during a bulk.
Alcohol also supplies calories (7 kcal/g) but isn't typically counted as a macro, since it isn't essential and doesn't fit the protein/carb/fat framework.
How this calculator works
Enter your stats, activity level, and goal:
How the split is calculated
The calculator first estimates TDEE (Mifflin-St Jeor BMR × activity factor), then adjusts calories by goal: −20% for fat loss, +10% for muscle gain, unchanged for maintenance. Macros are then allocated in this order:
- Protein: ~1.8 g per kg of body weight (within a common evidence-based range of 1.6–2.2 g/kg for people who exercise regularly).
- Fat: ~25% of total calories, a level that supports hormone production without crowding out other macros.
- Carbohydrate: the remaining calories after protein and fat are set, converted to grams.
Worked example
A 66 kg woman with a 2,000-calorie maintenance target choosing "lose fat": target calories ≈ 1,600. Protein ≈ 66×1.8 ≈ 119 g (476 kcal). Fat ≈ 25% of 1,600 = 400 kcal ≈ 44 g. Remaining carbs ≈ (1,600 − 476 − 400) ÷ 4 ≈ 181 g.
Common macro split approaches
| Approach | Typical split (P/C/F) | Best suited for |
|---|---|---|
| Balanced | 30/40/30 | General health, sustainable everyday eating |
| High-protein cut | 35/35/30 | Fat loss while preserving muscle |
| Low-carb | 30/20/50 | Those who feel better on fewer carbs |
| Performance/bulk | 25/50/25 | Endurance training or muscle/strength gain |
Same stats, three goals
For the 66 kg woman in the worked example (2,000 kcal maintenance), only the goal changes:
| Goal | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| Lose fat (−20%) | 1,600 | 119 g | 181 g | 44 g |
| Maintain | 2,000 | 119 g | 281 g | 56 g |
| Build muscle (+10%) | 2,200 | 119 g | 331 g | 61 g |
Which macro split fits your goal
The default split works for most people, but consider adjusting if:
- You're cutting and hungry often — shift a little more of your calories to protein and fiber-rich carbs, both of which improve fullness per calorie.
- You feel sluggish on lower carbs — raise carbs and lower fat slightly; total calories and protein matter more than the exact carb/fat ratio for most goals.
- You're training for endurance — favor the performance/bulk-style split with higher carbs to fuel longer training sessions.
- You have a diagnosed condition affecting metabolism (e.g. diabetes, kidney disease) — work with a registered dietitian rather than a generic split.
Benefits and limitations
Benefits: gives concrete daily targets that support specific goals — enough protein to protect muscle, enough fat for hormonal health, and a clear carb budget for energy.
Limitations: it's an estimate built on estimated TDEE, so real-world results depend on tracking accuracy and adjusting over time; it also doesn't account for individual conditions like insulin resistance or kidney disease, which change ideal macro ratios.
Expert tips
- Prioritize hitting your protein target consistently — it matters most for body composition and satiety.
- Spread protein across 3–4 meals rather than one large serving for better muscle protein synthesis.
- Treat the carb/fat split as flexible day to day, as long as total calories and protein stay on target.
- Re-run the calculator after meaningful weight changes or if your activity level shifts.
Common mistakes
- Chasing an aggressive deficit and cutting protein along with total calories, which accelerates muscle loss.
- Ignoring fiber and micronutrients while hitting macro numbers with low-quality food sources.
- Setting fat too low — below roughly 20% of calories can affect hormone production over time.
- Never adjusting targets as body weight changes throughout a diet or bulk.
Glossary
- Macronutrients
- Protein, carbohydrate, and fat — the calorie-providing nutrient categories.
- IIFYM
- "If It Fits Your Macros" — a flexible dieting approach focused on hitting gram targets rather than restricting specific foods.
- Caloric deficit/surplus
- Eating below or above maintenance calories to lose or gain weight respectively.
Frequently asked questions
A common evidence-based range for active adults is 1.6–2.2 grams of protein per kilogram of body weight per day, with higher amounts often used during a fat-loss phase to protect muscle.
There is no single "best" split — total calories matter most for fat loss — but higher protein (roughly 30–35% of calories) helps preserve muscle and control hunger during a deficit.
No — being within a reasonable range (a few grams either way) is generally fine. Consistency over weeks matters far more than daily precision.
Yes — the calculator's carb number can be shifted lower and fat raised to match a lower-carb preference, as long as total calories and protein stay similar.
Fat is calorie-dense (9 kcal/g vs. 4 for protein/carbs), so a modest percentage of calories can still meet essential fat needs while leaving more room for protein and carbs.
Sources & references
- International Society of Sports Nutrition Position Stand: protein — Journal of the International Society of Sports Nutrition
- Dietary Guidelines for Americans — U.S. Department of Agriculture (USDA)
Author & reviewer
Explore more free tools
The Macro Calculator is one of a growing suite of free, no-signup calculators.