Macro Calculator (Protein, Carbs & Fat)
Get your daily protein, carbohydrate and fat targets in grams — tailored to fat loss, maintenance or muscle gain.
TL;DR
Protein first: 1.6–2.2 g/kg depending on your goal. Fat at 25–30% of calories, carbs fill the rest. Enter your details and your split appears instantly. Everything runs in your browser — nothing is sent anywhere.
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What are macros and why do they matter?
Macronutrients — macros for short — are the three nutrient groups that provide energy: protein (4 kcal/g), carbohydrates (4 kcal/g) and fat (9 kcal/g). Total calories decide whether your weight goes up or down; your macro split decides whether the change comes from fat or muscle, how full you feel, and how strong you are in training.
How this calculator works
- BMR: your resting metabolism via the Mifflin-St Jeor equation (BMR calculator).
- TDEE and goal calories: BMR × activity multiplier gives your daily burn; a ~18% deficit is applied for fat loss, a ~12% surplus for muscle gain (calorie calculator).
- Macro split: protein is set first (1.6–2.0 g/kg by goal), then fat (25–28% of calories), and carbs fill the remaining calories.
Macro splits by goal
- Fat loss: protein at 2.0 g/kg — it protects muscle in a deficit and keeps you full. Fat ~28%, the rest carbs. Skimp on protein and a big share of the weight you lose will be muscle.
- Maintenance: protein at 1.6 g/kg with a balanced carb/fat split. Flexible and easy to sustain.
- Muscle gain: protein at 1.8 g/kg with carbs leading (~50% of calories) to fuel training volume and recovery.
Worked example: 70 kg, moderately active, cutting
Say the goal calories come out to 2,000 kcal:
- Protein: 70 × 2.0 = 140 g → 560 kcal
- Fat: 2,000 × 0.28 ÷ 9 ≈ 62 g → 560 kcal
- Carbs: remaining 880 kcal ÷ 4 = 220 g
Daily plan: 140 g protein, 220 g carbs, 62 g fat. For the full explanation, read our macro calculator guide.
Practical tips
- Hit protein first: nailing your protein target matters far more than matching the carb/fat ratio exactly.
- Spread it out: 25–40 g of protein across 3–5 meals stimulates muscle protein synthesis best. See how much protein per day for food examples.
- Don't chase ±5 g: macros are a compass, not a test. Being close on the weekly average is enough.
Not medical advice. If you have diabetes, kidney disease or another medical condition, plan your diet with a registered dietitian.
Frequently asked questions
What are macros?
Macronutrients are the three nutrient groups that provide energy: protein (4 kcal/g), carbohydrates (4 kcal/g) and fat (9 kcal/g). The same calories with a different macro split can feel — and build — very differently.
What macro split is best for fat loss?
Protein first: 1.6–2.2 g per kg of body weight in a deficit. Fat around 25–30% of calories, carbs fill the rest. High protein keeps you full and protects muscle.
What macro split is best for building muscle?
A small surplus (10–15% above TDEE) with 1.6–2.0 g protein per kg. Carbs fuel performance — roughly 45–55% of calories from carbs and 20–30% from fat works well for most lifters.
Do I have to track macros?
No, but tracking for a few weeks teaches portion sizes. After that, tracking just protein and total calories is enough for most people. A photo calorie app makes logging near effortless.
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