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A macro calculator takes your body stats and fitness goal and tells you exactly how many grams of protein, carbohydrates, and fat to eat each day. It starts with your Basal Metabolic Rate (the calories your body burns at rest), adjusts for your activity level to get your Total Daily Energy Expenditure, then applies your goal: a 500-calorie deficit for fat loss, maintenance for holding steady, or a 500-calorie surplus for muscle gain. From there it splits your target calories across the three macronutrients using a ratio that matches your diet style. Choose from six presets: Balanced (30/40/30), High Protein (40/30/30), Low Carb (35/20/45), Keto (20/5/75), Paleo (35/25/40), or IIFYM where you set your own percentages. Switch to Meal Breakdown mode and the calculator distributes your daily targets across 2 to 6 meals, with realistic portions for breakfast, lunch, dinner, and snacks. Smart insights flag whether your protein intake is in the optimal range for your body weight and warn you about very low calorie targets. Everything runs in your browser with no signup and no data collection.
Done with the Macro Calculator? Try this next:
Calorie Calculator →Choose imperial or metric units, then enter your gender, age, weight, and height. Select your activity level from the dropdown. The calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate.
Choose Cut (500-calorie deficit for fat loss), Maintain (stay at your current weight), or Bulk (500-calorie surplus for muscle gain). The calculator adjusts your target calories based on your selection.
Pick from Balanced, High Protein, Low Carb, Keto, Paleo, or IIFYM. Each preset uses a different protein/carbs/fat percentage split. Choose IIFYM to set your own custom percentages.
The calculator shows your BMR, TDEE, and target calories along with the exact grams of protein, carbs, and fat you need per day. The visual macro bar shows your split at a glance.
The insights panel checks whether your protein intake falls in the optimal range for your body weight (1.6 to 2.2g per kg for muscle building). It also warns about very low calorie targets or extreme macro ratios.
Click the Meal Breakdown tab and choose how many meals you eat per day (2 to 6). The calculator distributes your daily targets across breakfast, lunch, dinner, and snacks with per-meal calorie and macro cards.
Macro Calculator shows your daily protein, carb, and fat targets for any fitness goal. Includes six diet presets, meal-by-meal breakdown, and smart protein insights.
Daily Calories = BMR x Activity Multiplier +/- Calorie Adjustment
A 30-year-old male weighing 180 lbs (82 kg), 5'11" (180 cm) tall, who exercises 4 days per week and wants to build muscle.
A 28-year-old female weighing 140 lbs (64 kg), 5'5" (165 cm) tall, lightly active (yoga 2 days per week), wants to lose fat.
A 25-year-old male athlete weighing 200 lbs (91 kg), 6'1" (185 cm), training 6 days per week, wants to maintain current weight.
| Goal | Protein % | Carbs % | Fat % | Example (2,000 cal) |
|---|---|---|---|---|
| Fat Loss | 35 to 40% | 30 to 35% | 25 to 30% | 175g P / 150g C / 61g F |
| Muscle Building | 30 to 40% | 30 to 40% | 20 to 30% | 175g P / 188g C / 56g F |
| Maintenance | 25 to 30% | 40 to 50% | 25 to 30% | 138g P / 225g C / 61g F |
| Endurance Sports | 20 to 25% | 50 to 60% | 20 to 25% | 113g P / 275g C / 50g F |
| Keto / Low-Carb | 20 to 30% | 5 to 10% | 60 to 75% | 125g P / 50g C / 122g F |
| Balanced / General | 25 to 30% | 40 to 45% | 25 to 35% | 138g P / 213g C / 67g F |
Protein provides 4 calories per gram, carbs provide 4 calories per gram, and fat provides 9 calories per gram. Percentages should always total 100%.
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</p>Macros (macronutrients) are the three main nutrients your body needs in large amounts: protein, carbohydrates, and fat. Protein provides 4 calories per gram and is essential for muscle repair and growth. Carbohydrates provide 4 calories per gram and are your body's preferred energy source. Fat provides 9 calories per gram and supports hormone production, brain function, and nutrient absorption. Tracking macros gives you more control over your body composition than tracking calories alone.
First, calculate your Total Daily Energy Expenditure (TDEE) by multiplying your Basal Metabolic Rate by an activity factor. Then adjust for your goal: subtract calories for fat loss, add for muscle gain, or keep the same for maintenance. Finally, split the total calories into protein, carbs, and fat based on your diet style. This calculator does all of that automatically. You just enter your stats, pick a goal, and choose a macro split.
It depends on your goal and preferences. A balanced 30/40/30 (protein/carbs/fat) split works well for most people. If you are focused on building muscle, try high protein (40/30/30). If you respond well to lower carbs, try low carb (35/20/45). Keto (20/5/75) keeps carbs extremely low to induce ketosis. The best split is one you can stick to consistently, so start with balanced and adjust based on how you feel and perform.
Research consistently shows that 1.6 to 2.2 grams of protein per kilogram of body weight is optimal for building and maintaining muscle. For a 70 kg (154 lb) person, that is 112 to 154 grams per day. If you are cutting (losing fat), staying at the higher end of this range helps preserve muscle. If you are maintaining or bulking, the lower end is usually sufficient. This calculator shows your protein per kg so you can check whether your preset hits this range.
Counting calories tells you how much to eat. Counting macros tells you what to eat. Two diets with the same calorie count can produce very different results depending on macro composition. A high-protein diet preserves more muscle during a cut than a high-carb diet at the same calorie level. If your goal is general weight management, calorie counting may be enough. If you care about body composition (muscle vs fat), tracking macros is worth the extra effort.
Low carb typically means getting 20% to 25% of calories from carbohydrates, which is roughly 100 to 150 grams per day for most people. Keto is much more restrictive, keeping carbs to 5% to 10% of calories (usually under 50 grams per day) to push your body into ketosis, a metabolic state where you burn fat for fuel instead of glucose. Keto requires stricter tracking and can be harder to maintain, but some people find it effective for fat loss and appetite control.
There is no single best way to split macros across meals. The most important factor is hitting your daily totals. That said, spreading protein evenly across 3 to 5 meals (20 to 40 grams per meal) may slightly improve muscle protein synthesis compared to eating it all in one meal. The Meal Breakdown tab in this calculator distributes your targets across your chosen number of meals with breakfast slightly smaller and main meals slightly larger.
This calculator uses the Mifflin-St Jeor equation, which research shows is the most accurate BMR formula for most adults (within 10% of measured values). However, individual metabolism varies based on genetics, muscle mass, hormone levels, sleep, stress, and other factors. Treat the output as a starting point: follow the plan for 2 to 3 weeks, then adjust based on how your weight, energy levels, and performance change.
IIFYM stands for 'If It Fits Your Macros'. It is a flexible dieting approach where you can eat any food as long as it fits within your daily macro targets. There are no restricted foods. IIFYM focuses on hitting your protein, carb, and fat numbers rather than following a rigid meal plan. In this calculator, the IIFYM preset lets you set your own custom macro percentages rather than using a predefined split.
Yes. Every calculation runs entirely in your browser. Your age, weight, height, and other inputs are never sent to any server. No cookies, no tracking, no account required. You can safely use this calculator with your real measurements.
FreeToolPark. "Macro Calculator." FreeToolPark, 2026, www.freetoolpark.com/tools/macro-calculator. Accessed April 14, 2026.