Macro Calculator

How to Calculate Your Daily Macros

The macro calculator on this page estimates your TDEE using the Mifflin-St Jeor formula, then splits your daily calories into protein, carbohydrates, fat, and fiber targets based on your activity level and goal. TDEE is your BMR (calories at complete rest) multiplied by an activity factor — once calculated, the calculator applies a calorie adjustment for your goal and divides those calories using a balanced macro split.

The Mifflin-St Jeor BMR Formula

This calculator uses the Mifflin-St Jeor equation, published in 1990 and validated as the most accurate commonly used BMR formula for healthy adults. The formula:

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

TDEE = BMR × activity multiplier (1.2 for sedentary to 1.9 for very active). From TDEE, the calculator subtracts 500 calories for fat loss, adds 250 for muscle gain, or uses TDEE directly for maintenance.

Macro Split Explained

This calculator uses a balanced 30/40/30 macro split (protein/carbs/fat) as the default, which supports most general health and body composition goals:

• Protein (30% of calories): Essential for muscle repair, immune function, and satiety. At 30%, a 2,000 calorie diet provides 150g of protein — sufficient for most active adults.
• Carbohydrates (40% of calories): Primary fuel for the brain and high-intensity exercise. 200g from a 2,000-calorie diet is consistent with active-individual guidelines.
• Fat (30% of calories): Critical for hormonal function, fat-soluble vitamin absorption, and long-duration energy. About 67g from 2,000 calories.

If you are following a ketogenic diet, use the keto calculator instead — it uses a 5/25/70 carb/protein/fat split designed to maintain ketosis.

Adjusting Macros for Your Goal

The calorie adjustment for each goal is based on established guidelines:

• Fat loss (−500 cal): Creates a 500-calorie daily deficit, targeting approximately 1 lb/week of fat loss while preserving muscle mass with adequate protein
• Maintain (TDEE): Matches intake to expenditure for weight stability
• Muscle gain (+250 cal): A modest surplus that minimizes fat gain; for most people, 0.25–0.5 lbs of muscle gain per week is realistic

Track your weight loss percentage weekly to confirm the calorie targets are working for your actual metabolism — individual results vary significantly from calculator estimates.

How to Hit Your Macro Targets

• Track with an app — MyFitnessPal, Cronometer, or MacroFactor make food logging accurate and fast
• Prioritize protein first — protein is hardest to hit; plan your protein sources before other macros
• Batch prep carbs and fats — rice, oats, and olive oil are calorie-dense and easy to measure
• Use a food scale — volume measurements (cups, tablespoons) are far less accurate than weight in grams
• Aim for consistency over perfection — being within ±10% of your targets most days is sufficient for progress

Macronutrient Caloric Density and Meal Planning

Understanding caloric density helps you plan meals that hit your macro targets without exceeding calories. The three macronutrients have different caloric densities per gram:

• Protein: 4 kcal/g — chicken breast (165 cal/100g), Greek yogurt (59 cal/100g), eggs (155 cal/100g)
• Carbohydrates: 4 kcal/g — white rice (130 cal/100g cooked), oats (71 cal/100g cooked), sweet potato (86 cal/100g)
• Fat: 9 kcal/g — olive oil (884 cal/100g), avocado (160 cal/100g), almonds (579 cal/100g)

Fat's high caloric density means small amounts significantly impact total calories. A single tablespoon of olive oil adds 120 calories — easy to undercount. Lean proteins and high-volume vegetables give the most food bulk per calorie, making them essential for satiety during fat loss.

When to Recalculate Your Macros

Your TDEE and macro targets change as your body composition and activity level change. Recalculate whenever: you lose or gain 10+ lbs, your activity level changes significantly (starting or stopping a sport or job), you shift goals from fat loss to maintenance or muscle gain, or your progress stalls for 3+ weeks despite consistency. The Mifflin-St Jeor formula used here accounts for current body weight — a lighter body needs fewer calories, so failing to recalculate after significant weight loss is a common reason plateaus occur. For specialized dietary approaches, compare your results with the keto calculator to see how a low-carb split compares.