Macro Calculator
Calculate daily protein, carbohydrate, and fat targets based on your body stats, activity level, and fitness goal.
| Macro | Grams/day | Calories | Cal/g |
|---|---|---|---|
| Protein | 230 g | 922 | 4 |
| Carbohydrates | 230 g | 922 | 4 |
| Fat | 88 g | 790 | 9 |
Protein per kg bodyweight: 3.07 g/kg (1.39 g/lb)
For informational purposes only. Consult a registered dietitian or healthcare professional before making dietary changes.
For informational purposes only. Consult a registered dietitian or healthcare professional before making significant dietary changes.
What Are Macronutrients?
Macronutrients — commonly called "macros" — are the three main classes of nutrients that supply energy (calories) to the body: protein, carbohydrates, and fat. Every food you eat contains some combination of these three, and the ratio in which you consume them has a significant effect on body composition, energy levels, and athletic performance.
Unlike micronutrients (vitamins and minerals), which are needed in small amounts, macronutrients are consumed in large quantities every day. Understanding your macro requirements allows you to build a diet that supports your specific goals rather than simply guessing at portion sizes or relying on generic advice.
The Three Macros Explained
Protein — 4 Calories per Gram
Protein is composed of amino acids, which are the building blocks used to repair and build muscle tissue, produce enzymes and hormones, and support immune function. When you exercise, muscle fibers sustain micro-tears that protein repairs during recovery — this process is what causes muscles to grow larger and stronger over time.
Protein also has the highest thermic effect of all macronutrients: the body uses 20–30% of protein's calories just to digest it, compared to 5–10% for carbohydrates and 0–3% for fat. This gives high-protein diets a modest metabolic advantage. Most research supports 1.6–2.2 g of protein per kg of body weight per day for people who exercise regularly. Sedentary individuals need only 0.8 g/kg (the RDA), but even modest physical activity pushes optimal intake higher.
Carbohydrates — 4 Calories per Gram
Carbohydrates are the body's preferred fuel source, especially for high-intensity exercise. They are broken down into glucose, which either fuels working muscles immediately or is stored as glycogen in the liver and muscles for later use. During intense exercise, glycogen is the primary energy source — this is why carbohydrate intake is especially important for athletes and those doing high-intensity training.
The ideal carbohydrate intake varies widely. Someone doing daily endurance training may need 5–7 g/kg, while a sedentary person may function well on 2–3 g/kg. Low-carb approaches can be effective for fat loss and metabolic health, but they are generally not optimal for performance in sports requiring explosive power or sustained high-intensity effort.
Fat — 9 Calories per Gram
Dietary fat has the highest caloric density of the three macros — more than twice the calories per gram of protein or carbohydrate. Fat is essential for the absorption of fat-soluble vitamins (A, D, E, K), the production of sex hormones including testosterone and estrogen, brain health (the brain is about 60% fat), and insulation and protection of organs.
Fat intake should generally not drop below 20% of total calories for extended periods, as very low fat intake impairs hormone production and fat-soluble vitamin absorption. In a ketogenic diet, fat is raised to 70%+ of calories to induce ketosis — the metabolic state where the body burns fat as its primary fuel instead of glucose.
How TDEE Is Used to Calculate Macros
This calculator first estimates your Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation for BMR and an activity multiplier. Your TDEE is your maintenance calorie level — the number of calories that will keep your weight stable. From there:
- Weight loss: TDEE minus 500 calories per day ≈ 0.45 kg (1 lb) loss per week
- Muscle gain: TDEE plus 300 calories per day — a moderate surplus that minimizes fat gain
- Maintenance: Eat at TDEE to hold current weight
Once the calorie target is set, the selected diet preset determines what percentage of those calories come from each macro. Grams are calculated by dividing calorie allocation by the caloric density: protein and carbs at 4 cal/g, fat at 9 cal/g.
Diet Presets Compared
| Preset | Fat % | Protein % | Carbs % | Best For |
|---|---|---|---|---|
| Balanced | 30% | 35% | 35% | General fitness, most people |
| Low-Carb | 40% | 35% | 25% | Fat loss, blood sugar control |
| Keto | 70% | 25% | 5% | Strict carb restriction, ketosis |
| High-Protein | 30% | 50% | 20% | Muscle building, body recomposition |
Protein Per Kilogram — Reference Table
| Population | Protein (g/kg/day) |
|---|---|
| Sedentary adult | 0.8 |
| Recreationally active adult | 1.2–1.6 |
| Endurance athlete | 1.4–1.6 |
| Strength / power athlete | 1.6–2.2 |
| Dieting to preserve muscle | 2.0–2.4 |
| Older adults (65+) | 1.2–1.6 |
Frequently Asked Questions
What are macros and why do they matter?
Macronutrients (macros) are the three main categories of nutrients that provide calories: protein, carbohydrates, and fat. Protein provides 4 calories per gram and is essential for muscle repair and growth. Carbohydrates also provide 4 calories per gram and are the body's primary fuel source. Fat provides 9 calories per gram and is critical for hormone production, brain function, and fat-soluble vitamin absorption. Tracking macros helps ensure that your total calorie intake is composed of the right proportions for your specific goal — whether that is fat loss, muscle gain, or improved athletic performance.
How much protein do I need per day?
Protein requirements depend on body weight and activity level. The general RDA (Recommended Dietary Allowance) is 0.8 g/kg for sedentary adults, but research consistently shows that physically active people benefit from 1.6–2.2 g/kg body weight per day. For those in a calorie deficit trying to preserve muscle, 2.0–2.4 g/kg is recommended. The American College of Sports Medicine recommends 1.2–2.0 g/kg for endurance and strength athletes. As a practical rule: aim for at least 1.6 g/kg if you exercise regularly.
What is the difference between low-carb, keto, and balanced diets?
A balanced diet (roughly 30F/35P/35C by calories) is suitable for most people doing moderate exercise and provides flexibility for food choices. A low-carb diet (40F/35P/25C) reduces carbs moderately, which can aid fat loss and improve blood sugar control without requiring strict restriction. A ketogenic diet (70F/25P/5C) is extremely low in carbohydrates — typically under 50g per day — which forces the body to enter ketosis, burning fat as its primary fuel. Keto can be effective for weight loss and certain medical conditions but is restrictive and difficult to maintain long-term for many people.
Can I build muscle in a calorie deficit?
Yes, but only under specific conditions. "Body recomposition" — simultaneously losing fat and gaining muscle — is most effective for beginners to strength training, people returning after a long break, and those with significant body fat to lose. For intermediate and advanced trainees, muscle gain is far more efficient in a calorie surplus (bulking phase). A moderate surplus of 200–300 calories above TDEE with high protein intake (2.0+ g/kg) is the most common approach for lean muscle gain.
Should I count calories or just count macros?
Macros and calories are not alternatives — your macros determine your calories. If you hit your macro targets, you automatically hit your calorie target. Counting macros is generally considered superior to counting only calories because it ensures you eat sufficient protein (protecting muscle), appropriate fat (for hormones), and the right amount of carbohydrates for your energy demands. Most nutrition coaching apps track both simultaneously. If you are just starting out, tracking only calories is simpler and still effective for weight management.
How accurate is this macro calculator?
This calculator uses the Mifflin-St Jeor equation to estimate BMR, which studies show predicts actual resting metabolic rate within about 10% for most healthy adults. The activity multiplier is the largest source of error — most people overestimate how active they are. Use the results as a starting point, track your weight for 2–3 weeks, and adjust your calorie target by 100–200 calories up or down based on actual weight changes.
Related Calculators
- Calorie Calculator — Daily calorie needs by activity level
- TDEE Calculator — Total Daily Energy Expenditure with goal table
- BMI Calculator — Body Mass Index with WHO categories
- Protein Calculator — Daily protein needs based on weight and goal