Macro Calculator
Calculate your optimal macronutrient split (Protein/Carbs/Fats).
Moderately Active
Regular gym sessions, sports, or active job
Macronutrients are the three main nutrients your body needs in large quantities: protein, fats, and carbohydrates. Unlike micronutrients (vitamins and minerals) needed in small amounts, macros provide the energy and building blocks for all bodily functions.
Each macronutrient serves unique purposes and provides different amounts of energy per gram. Understanding their roles helps you optimize your diet for your specific goals, whether that's fat loss, muscle gain, or performance optimization.
Protein (4 calories per gram)
Protein is made up of amino acids, which are the building blocks of muscle tissue, enzymes, hormones, and antibodies. Your body can produce some amino acids, but nine are essential and must come from food. Protein has the highest thermic effect (20-30% of calories burned during digestion) and is the most satiating macro.
Fats (9 calories per gram)
Dietary fats are essential for hormone production (including testosterone and estrogen), vitamin absorption (A, D, E, K), brain function, and cell membrane structure. Despite having more than twice the calories per gram of protein or carbs, fats are necessary for health and don't inherently make you fat - total calories do.
Carbohydrates (4 calories per gram)
Carbs are your body's preferred energy source, especially for high-intensity exercise and brain function. They're stored as glycogen in muscles and liver, providing quick energy. While not technically "essential" (your body can make glucose from protein/fat), carbs improve training performance, recovery, and make dieting more sustainable for most people.
The calculator uses a hierarchical approach to setting macros: protein first, fat second, carbs fill the remainder. This ensures you meet essential needs while optimizing for your goal.
Step 1: Set Protein
Protein is prioritized because it's essential for muscle preservation and growth. Research suggests:
- Fat loss: 2.0-2.6g per kg (0.9-1.2g per lb) - higher protein preserves muscle in a deficit
- Maintenance: 1.6-2.0g per kg (0.7-0.9g per lb) - sufficient for muscle maintenance
- Muscle gain: 1.6-2.2g per kg (0.7-1.0g per lb) - adequate for muscle protein synthesis
Step 2: Set Fat Minimum
Fats should generally be 20-35% of total calories. Going below 15-20% can impair hormone production. The calculator sets fat at 25% for fat loss (to maximize protein and allow some carbs) and 30% for muscle gain (higher total calories makes room for more fat).
Step 3: Fill with Carbs
After protein and fat are set, remaining calories come from carbs. Carbs aren't essential but improve training performance, recovery, and diet adherence. Active individuals typically perform better with higher carbs. Sedentary people may prefer more fat, fewer carbs.
Pro tip: These are starting points. After 2-3 weeks, adjust based on hunger, energy, and training performance. Some people feel better on higher carbs, others on higher fats. As long as you hit protein and calories, you have flexibility with fat/carb distribution.
Tracking macros might seem daunting initially, but it becomes second nature with practice. Here's how to do it effectively:
Essential Tools
- Food scale: Most important tool. Weigh everything in grams for accuracy. "Eyeballing" portions is notoriously inaccurate
- Tracking app: MyFitnessPal, Cronometer, or MacroFactor. Scan barcodes and save frequent meals for quick logging
- Measuring cups/spoons: For liquids and foods difficult to weigh
What to Track
- All foods and beverages (except water, black coffee, tea)
- Cooking oils and butter - very calorie-dense
- Sauces, condiments, and dressings
- Alcohol (7 calories per gram)
- "Bites, licks, and tastes" while cooking
Tips for Accuracy
- Weigh raw ingredients when possible (meat, grains lose water when cooked)
- Use USDA entries in tracking apps for accuracy
- For restaurant meals, overestimate by 20% (they use more oil/butter than you think)
- Meal prep for consistency - eating the same meals makes tracking easier
- Don't stress about ±5g variations - weekly averages matter more
When Can You Stop Tracking?
After 6-12 weeks of consistent tracking, many people learn portion sizes well enough to estimate accurately. However, if progress stalls, return to tracking for a week to ensure you haven't drifted off target. Some people prefer to track long-term for accountability and consistency.
Frequently Asked Questions
Macronutrients (macros) are the three main nutrients your body needs in large amounts: protein, fats, and carbohydrates. Each serves specific functions and provides energy (calories). Protein: 4 calories/gram, Carbohydrates: 4 calories/gram, Fats: 9 calories/gram. Balancing macros optimizes energy, body composition, and health.
Protein is prioritized because it's essential for muscle maintenance and growth, has the highest thermic effect (burns 20-30% of its calories during digestion), and increases satiety better than carbs or fats. During fat loss, high protein preserves muscle mass. For muscle gain, adequate protein is required for repair and growth.
Yes! The calculator provides evidence-based recommendations, but individual preferences matter. Some people perform better on higher carbs, others on higher fats. As long as you: 1) Hit your protein target, 2) Get minimum 0.5g/kg fat for hormones, 3) Stay within your calorie target, you can adjust carbs and fats based on preference and performance.
No. Weekly averages matter more than daily precision. Aim to hit protein consistently (most important), then total calories, then fat minimum. Carbs can fluctuate day-to-day. Some people eat more carbs on training days and less on rest days (carb cycling) while keeping weekly totals on target.
Food labels can be off by 10-20%, and portion estimation introduces more error. Use a food scale for accuracy, especially for calorie-dense foods like oils, nuts, and nut butters. Track everything for 2-4 weeks to learn portion sizes, then you can estimate more accurately. Apps like MyFitnessPal or Cronometer make tracking easier.
Yes. Recalculate every 5-10 pounds (2-5 kg) of weight change. As you lose weight, your calorie needs decrease and protein needs (in grams) decrease slightly. As you gain muscle, your calorie needs increase. Use the same macros for 4-6 weeks before recalculating unless progress stalls.
No. While protein is important, fats are essential for hormone production, vitamin absorption, and cellular function. Carbs aren't technically essential but provide energy for high-intensity exercise and cognitive function. Extremely low fat (<15% calories) can disrupt hormones. Extremely low carb may impair training performance.
Neither is inherently better - total calories matter most for fat loss. Some people find low-carb more satiating, others prefer low-fat. Research shows similar fat loss when protein and calories are matched. Choose the approach you can sustain long-term. Most people do well with moderate amounts of both (20-35% fat, remainder carbs).
Medical Disclaimer
This macro calculator provides general recommendations. Individual needs may vary based on genetics, health conditions, training intensity, and other factors. Consult with a registered dietitian or sports nutritionist for personalized nutrition advice.