Macro Calculator (IIFYM)
Want to know exactly how much protein, carbs, and fat to eat each day? Enter your stats and goal and you'll get a personalised macro breakdown. Based on the IIFYM flexible dieting approach - no foods are off limits, just numbers to hit.
How to use
- Enter your age, gender, weight, and height. Pick whatever units you're used to.
- Choose your activity level. Be honest - most people overestimate this.
- Pick your goal: lose weight, maintain, or build muscle.
- Hit Calculate to see your daily calorie target and how it splits into protein, carbs, and fat.
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IIFYM (If It Fits Your Macros) is a flexible dieting approach where you track your daily intake of protein, carbohydrates, and fat rather than following a rigid meal plan. As long as your macros fit your targets, you can eat any foods you enjoy. This approach is popular because it allows flexibility while still achieving fat loss, muscle gain, or maintenance goals.
Your macro targets are derived from your Total Daily Energy Expenditure (TDEE), the number of calories your body burns per day based on your weight, height, age, gender, and activity level. Protein is set based on body weight (typically 1.6–2.2g per kg for muscle gain), fat covers essential hormonal and cellular functions (0.8–1g per kg), and carbohydrates fill the remaining calorie budget. Adjusting your goal between cut, bulk, or maintain shifts the calorie total and macro split accordingly.
Frequently Asked Questions
What is IIFYM (If It Fits Your Macros)?
IIFYM is a flexible dieting method where you track protein, carbohydrates, and fat rather than following a strict meal plan. If a food fits within your daily macro targets, you can eat it. It works for fat loss, muscle gain, and maintenance. The macro targets change but the flexibility stays the same.
How much protein do I need per day?
For muscle gain: 1.6–2.2g of protein per kg of body weight. For fat loss: 2.0–2.4g per kg (higher protein preserves muscle during a calorie deficit). For maintenance: 1.2–1.6g per kg. A 70 kg person building muscle needs 112–154g of protein per day.
What is the best macro split for fat loss?
A common fat loss macro split is 40% protein, 35% carbohydrates, 25% fat. High protein preserves muscle mass during a calorie deficit, carbs fuel workouts, and fat supports hormones. The calorie total matters most; macros fine-tune body composition. Eat 300–500 calories below your TDEE to lose ~0.5 kg per week.
What is the best macro split for muscle gain?
For muscle gain (bulking), a common split is 30% protein, 50% carbohydrates, 20% fat. Carbs provide energy for intense training and aid recovery. Eat 250–500 calories above your TDEE. Aim for 1.6–2.2g protein per kg. Gaining 0.25–0.5 kg per week minimises fat gain while building muscle.
How is TDEE calculated?
TDEE (Total Daily Energy Expenditure) = BMR × Activity Multiplier. BMR is your base metabolic rate (calories burned at rest, calculated from weight, height, age, and gender using the Mifflin-St Jeor formula). The activity multiplier ranges from 1.2 (sedentary) to 1.9 (very active). This total is your maintenance calorie level.