What this tool does
The Macro Calculator determines your ideal daily intake of protein, carbohydrates, and fat based on your personal stats, activity level, and fitness goal. It first calculates your Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation, then applies goal-specific calorie adjustments (deficit for weight loss, surplus for muscle building), and finally distributes those calories across the three macronutrients using evidence-based ratios. The tool displays your daily targets in both grams and calories for each macro, shows the percentage distribution in a visual pie chart, provides per-meal breakdowns across 3 meals and 2 snacks, and reports your underlying BMR and TDEE for reference. This gives you a complete, actionable nutrition plan rather than just a calorie number.
How it calculates
The calculator follows a three-step process:
**Step 1 - Calculate BMR (Mifflin-St Jeor equation):** - Male: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5 - Female: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age - 161
**Step 2 - Calculate TDEE and adjust for goal:** - TDEE = BMR x Activity Multiplier (1.2 to 1.9) - Weight Loss: TDEE - 500 calories - Maintenance: TDEE (no change) - Muscle Building: TDEE + 300 calories
**Step 3 - Apply macro splits:** - Weight Loss: 40% protein / 30% carbs / 30% fat (high protein preserves muscle during deficit) - Maintenance: 30% protein / 40% carbs / 30% fat (balanced distribution) - Muscle Building: 35% protein / 45% carbs / 20% fat (carbs fuel training, protein supports growth)
Gram conversions: Protein and carbs provide 4 calories per gram. Fat provides 9 calories per gram. Meal distribution follows a 25/10/30/10/25 pattern across breakfast, morning snack, lunch, afternoon snack, and dinner.
Who should use this
- People starting a structured diet who need specific macro targets rather than just a calorie number - Gym-goers and bodybuilders who need to hit protein targets while managing overall calorie intake - Athletes in training who need sufficient carbohydrates for performance while controlling body composition - Anyone transitioning between fitness goals (from cutting to bulking, or vice versa) who needs new targets - Meal preppers who want per-meal macro breakdowns to plan weekly cooking sessions
Worked examples
**Example 1: Male building muscle** A 28-year-old male, 80 kg, 180 cm, active (6-7 days/week), goal: build muscle. - BMR = 10(80) + 6.25(180) - 5(28) + 5 = 1,790 cal - TDEE = 1,790 x 1.725 = 3,088 cal - Target = 3,088 + 300 = 3,388 cal - Protein: 35% = 1,186 cal = 297g - Carbs: 45% = 1,525 cal = 381g - Fat: 20% = 678 cal = 75g - Lunch (30%): 1,016 cal, 89g protein, 114g carbs, 23g fat
**Example 2: Female losing weight** A 35-year-old female, 68 kg, 165 cm, moderately active, goal: lose weight. - BMR = 10(68) + 6.25(165) - 5(35) - 161 = 1,371 cal - TDEE = 1,371 x 1.55 = 2,125 cal - Target = 2,125 - 500 = 1,625 cal - Protein: 40% = 650 cal = 163g - Carbs: 30% = 488 cal = 122g - Fat: 30% = 488 cal = 54g
**Example 3: Sedentary maintenance** A 50-year-old male, 75 kg, 172 cm, sedentary, goal: maintain. - BMR = 10(75) + 6.25(172) - 5(50) + 5 = 1,580 cal - TDEE = 1,580 x 1.2 = 1,896 cal - Protein: 30% = 569 cal = 142g - Carbs: 40% = 758 cal = 190g - Fat: 30% = 569 cal = 63g
Limitations
- The Mifflin-St Jeor equation provides population-average estimates; individuals with unusually high or low muscle mass may see different actual requirements - Macro ratios are general guidelines based on sports nutrition research; optimal splits vary by individual response, training specifics, and dietary preferences - The calculator does not account for micronutrient needs, fiber intake, or food quality, all of which significantly impact health outcomes - Per-meal breakdowns assume equal macro distribution; in practice, pre- and post-workout nutrition timing may benefit from carb and protein loading around training sessions - People with diabetes, kidney disease, or other conditions affecting macronutrient metabolism should consult their healthcare provider rather than using generic ratios
FAQs
Q: Why is protein set so high for weight loss? A: During a calorie deficit, higher protein intake (around 1.6-2.2g per kg of body weight) helps preserve lean muscle mass while losing fat. The 40% protein allocation during weight loss typically falls within this evidence-based range and helps with satiety.
Q: Can I adjust the macro ratios to my preference? A: This calculator uses evidence-based starting ratios for each goal. While individual needs vary, these ratios are a solid starting point. Track your results for 2-4 weeks, then adjust based on energy levels, training performance, and body composition changes.
Q: How important is hitting exact macro targets? A: Consistency matters more than precision. Aim to be within 5-10g of each macro target daily. Protein is the most important to hit consistently, followed by total calories. The carb-to-fat ratio is more flexible and can shift based on food preferences.
Q: Should I eat differently on rest days versus training days? A: Some people benefit from higher carbs on training days and slightly lower carbs on rest days while keeping protein constant. This calculator provides a daily average; you can distribute carbs more toward training days as long as the weekly total stays consistent.
Explore Similar Tools
Explore more tools like this one:
- Macro Nutrient Calculator — Calculate your personalized daily calorie and... - Keto Calculator — Calculate daily calorie and macronutrient targets for... - Calories to Grams — Convert your daily calorie target into specific... - Grams to Calories — Convert macronutrient grams (Protein, Carbs, Fat,... - Protein Calculator — Calculate daily protein requirements based on body...