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Macro Calculator

Calculate your personalized daily protein, carbohydrate, and fat targets based on your body stats, activity level, and fitness goal — fat loss, muscle gain, or maintenance.

Last Updated: May 2026
Live Interactive Calculator
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1. Calorie & Diet Target

2. Macro Customizer & Meals

Ratios are locked to standard ratios of the chosen diet plan. Select "Custom Ratio..." to customize sliders manually.

What Are Macros and Why Do They Matter?

Calories tell you how much to eat. Macros tell you what to eat. While a calorie deficit is the fundamental driver of fat loss, the ratio of protein, carbohydrates, and fat in your diet determines whether you lose fat, muscle, or both — and how you feel while doing it.

The practice of tracking macronutrients, often called IIFYM (If It Fits Your Macros), has become the gold standard for body composition management among athletes, bodybuilders, and everyday fitness enthusiasts.

The Mifflin-St Jeor Formula: How We Calculate Your Calorie Base

Your macro targets start with your Basal Metabolic Rate (BMR) — the number of calories your body burns at complete rest. We use the Mifflin-St Jeor equation, which research consistently shows is the most accurate BMR predictor for most adults:

  • Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
  • Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

Your BMR is then multiplied by an activity factor (1.2 to 1.9) to produce your Total Daily Energy Expenditure (TDEE) — your true maintenance calories.

Goal-Based Macro Splits

Once your calorie target is set, it's divided into macronutrients based on your goal:

  • Fat Loss: High protein (~35%) to preserve muscle in a deficit, moderate fat (~30%), controlled carbs (~35%).
  • Muscle Gain: Elevated protein (~30%) and carbohydrates (~45%) to fuel workouts and recovery, moderate fat (~25%).
  • Maintenance: Balanced split — protein (~25%), carbs (~50%), fat (~25%) — to sustain weight and energy levels.

How to Use Your Macro Results

  1. Use a food tracking app (MyFitnessPal, Cronometer) to log daily intake.
  2. Prioritize hitting your protein target first — it's the hardest to achieve and most critical.
  3. Fill remaining calories with carbs and fats based on your preference and lifestyle.
  4. Reassess every 4–6 weeks as your weight changes and adjust accordingly.

Frequently Asked Questions

What are macros (macronutrients)?

Macronutrients are the three main categories of nutrients that provide your body with energy: Protein (4 calories per gram), Carbohydrates (4 calories per gram), and Fat (9 calories per gram). Tracking macros — often called 'If It Fits Your Macros' (IIFYM) — gives you precise control over your body composition beyond just counting total calories.

How does the macro calculator determine my targets?

The calculator first estimates your Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor BMR formula adjusted for your activity level. It then applies a calorie modifier based on your goal (e.g., -500 cal for fat loss, +300 cal for muscle gain) and splits the adjusted calories into protein, carb, and fat ratios based on established nutritional guidelines.

How much protein do I actually need per day?

For active individuals looking to build or preserve muscle, the research-backed recommendation is 0.7 to 1.0 grams of protein per pound of bodyweight (1.6 to 2.2 g/kg). Our calculator targets the higher end for muscle gain goals and moderate amounts for fat loss to preserve lean mass while in a calorie deficit.

What is the difference between fat loss and cutting macros?

Both involve a calorie deficit, but the macro split differs. A 'fat loss' approach uses a moderate deficit (~500 cal/day) with higher protein to preserve muscle. More aggressive 'cutting' phases use a larger deficit with even higher protein ratios. Our calculator provides the evidence-based moderate approach suitable for sustainable fat loss.

Should I eat the same macros every day?

Consistency is key for results, but many athletes use 'macro cycling' — higher carbs on training days and lower carbs on rest days while keeping weekly averages consistent. Our calculator gives you your daily targets as a starting baseline. You can adjust based on your training schedule.

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