🥩 Macro Calculator
Calculate your ideal daily protein, carbs, and fat targets based on your body and goals.
What Are Macros and Why Do They Matter?
Macronutrients — or "macros" — are the three main categories of nutrients your body uses for energy: protein, carbohydrates, and fat. Alcohol is sometimes counted as a fourth macro. Each has a specific caloric value:
- Protein — 4 calories per gram. Builds and repairs muscle tissue, keeps you full longer, and supports immune function. Especially important if you exercise regularly.
- Carbohydrates — 4 calories per gram. Your body's preferred fuel source for high-intensity activity and brain function. Includes sugars, starches, and fiber.
- Fat — 9 calories per gram. Essential for hormone production, vitamin absorption, and cell membrane health. Higher calorie density means smaller portions matter more.
Tracking macros — rather than just total calories — gives you a more precise way to reach body composition goals. Two people can eat the same number of calories but get very different results depending on how those calories are split between protein, carbs, and fat.
How This Calculator Works
Your daily calorie target is calculated using the Mifflin-St Jeor equation (the most validated formula for estimating BMR), then adjusted for your activity level. Your macro targets are then derived from that calorie number based on your goal: cutting, maintaining, or building muscle.
Common Macro Split Ratios
| Goal | Protein | Carbs | Fat |
|---|---|---|---|
| Weight Loss | 40% | 30% | 30% |
| Maintenance | 30% | 40% | 30% |
| Muscle Gain | 30% | 50% | 20% |
| Low Carb / Keto | 25% | 5% | 70% |
| Endurance Athlete | 20% | 60% | 20% |
FAQs
When to Use This Calculator
Use this when starting a structured nutrition plan for fat loss, muscle building, or athletic performance. It gives you daily protein, carb, and fat targets calibrated to your body size, activity, and goal.
Common Mistakes to Avoid
- Setting calories too aggressively — cutting more than 500 calories below TDEE can cause muscle loss; aim for a moderate deficit.
- Ignoring fiber and micronutrients — hitting macro numbers with only processed foods will not support long-term health.
- Not adjusting as you progress — as you lose weight, your TDEE decreases; recalculate your macros every 10–15 lbs of change.