Macro Nutrient Calculator

Macronutrients ('macros') are the three primary nutrients your body needs in large amounts: PROTEIN (4 calories/gram) builds and repairs muscle, supports immune function, and creates enzymes and hormones. CARBOHYDRATES (4 calories/gram) are your body's preferred energy source, fueling brain function, exercise, and daily activities. FATS (9 calories/gram) support hormone production, nutrient absorption (vitamins A, D, E, K), cell membrane health, and provide concentrated energy. The ratio in which you consume these macros affects body composition, energy levels, performance, and health outcomes. While total calories determine weight change, macro ratios influence whether you gain/lose fat or muscle, how satiated you feel, workout performance, and metabolic health markers.

TDEE stands for Total Daily Energy Expenditure—the total number of calories you burn each day. It consists of: (1) BMR (Basal Metabolic Rate): Calories burned just to keep you alive at rest (60-75% of TDEE). (2) TEF (Thermic Effect of Food): Calories burned digesting food (about 10%). (3) NEAT (Non-Exercise Activity Thermogenesis): Calories from daily movement, fidgeting, walking (15-30%). (4) EAT (Exercise Activity Thermogenesis): Calories from intentional exercise (5-15%). TDEE is calculated by multiplying your BMR by an activity factor. Eating below your TDEE creates a caloric deficit (weight loss); eating above creates a surplus (weight gain). TDEE is an estimate—individual variations of 200-300 calories are common. Track progress and adjust as needed.

For most people, the MIFFLIN-ST JEOR formula (1990) is considered most accurate, with about 10% estimation error in clinical studies. It's the default in our calculator. HARRIS-BENEDICT (1919, revised 1984) is the classic formula but tends to overestimate BMR by 5% in overweight individuals. KATCH-MCARDLE uses lean body mass instead of total weight, making it more accurate for very lean or very muscular individuals—but requires knowing your body fat percentage. If you know your body fat, enter it in our calculator to use Katch-McArdle automatically. No formula is perfect for everyone due to individual metabolic variation, but these provide solid starting points that can be refined based on real-world progress.

Protein needs depend on activity level and goals: SEDENTARY ADULTS: 0.8g per kg (0.36g per lb) of body weight—the RDA minimum to prevent deficiency. ACTIVE/EXERCISING: 1.2-1.6g per kg (0.55-0.73g per lb)—supports recovery and muscle maintenance. MUSCLE BUILDING: 1.6-2.2g per kg (0.73-1g per lb)—maximizes muscle protein synthesis during strength training. FAT LOSS (while preserving muscle): 1.8-2.4g per kg (0.82-1.1g per lb)—higher protein during caloric deficit prevents muscle loss. Research shows no significant additional benefit above 2.2g/kg for most people. Spread protein intake across meals (20-40g per meal) for optimal muscle protein synthesis rather than consuming most in one meal.

There's no universally 'best' ratio—total calories matter most for weight loss. However, research-supported guidelines for fat loss while preserving muscle include: HIGHER PROTEIN (25-35%) helps preserve lean mass, increases satiety, and has the highest thermic effect. MODERATE FAT (20-35%) maintains hormone function, especially important for longer cuts. FLEXIBLE CARBS (remaining calories) fill the rest based on personal preference and training demands. A common effective split is 30/35/35 (P/C/F) for moderate fat loss or 35/35/30 for aggressive cuts. Low-carb and keto approaches (5-25% carbs) can work but aren't necessarily superior unless they help you adhere to your calorie target. The 'best' ratio is one you can sustain consistently. Choose based on food preferences, workout needs, and what keeps you satisfied.

The ketogenic diet is a very low-carb, high-fat diet (typically 70-75% fat, 20-25% protein, 5% carbs—roughly 20-50g carbs/day). It forces your body into ketosis, where fat becomes the primary fuel source instead of carbohydrates. POTENTIAL BENEFITS: Rapid initial weight loss (mostly water), appetite suppression, stable blood sugar/energy for some people. CONSIDERATIONS: Requires strict carb tracking, may impair high-intensity exercise initially, potential 'keto flu' during adaptation, limits food choices significantly. Not necessarily superior for fat loss compared to other approaches at equal calories and protein. Works well for some people as a behavioral tool for reducing calorie intake. Our calculator includes a keto preset (25% protein, 5% carbs, 70% fat) if you want to try this approach.

For muscle gain (bulking), you need: (1) CALORIC SURPLUS: Eat 250-500 calories above TDEE. Smaller surplus (lean bulk) minimizes fat gain; larger surplus builds muscle faster but adds more fat. (2) ADEQUATE PROTEIN: 1.6-2.2g per kg (0.7-1g per lb) of bodyweight. More protein doesn't mean more muscle—there's a ceiling. (3) SUFFICIENT CARBS: Fuel for training intensity and recovery. 40-50% of calories is common for bulking. (4) ADEQUATE FAT: At least 20-25% of calories for hormonal health. Our 'High Protein' preset (40% protein, 35% carbs, 25% fat) is designed for muscle-building emphasis. Combined with the 'Lean Bulk (+250)' or 'Standard Bulk (+500)' goal, this gives you an appropriate muscle-building approach.

It depends on your goals and preferences. CALORIE-ONLY TRACKING is simpler and sufficient for basic weight loss if you're not concerned with body composition specifics. Good for beginners or those easily overwhelmed. MACRO TRACKING is more precise and recommended when: (1) You want to optimize muscle gain/retention. (2) You're an athlete needing performance nutrition. (3) You've plateaued with calorie-only approaches. (4) You want to understand your eating patterns better. IIFYM ('If It Fits Your Macros') is a flexible approach where you can eat any foods that fit your daily macro targets. A middle ground: Track calories + protein only. Protein is the most important macro for body composition; carbs and fats can flex as long as calories are controlled.

The Zone Diet, created by Dr. Barry Sears, prescribes a 40% carbs / 30% protein / 30% fat ratio at every meal. The theory is that this ratio optimizes hormonal balance (particularly insulin and eicosanoids) for fat loss, mental clarity, and reduced inflammation. EVIDENCE: While the ratio isn't uniquely magical, it's a reasonable balanced approach that emphasizes: adequate protein, moderate carbs (typically from low-glycemic sources), and healthy fats. Research hasn't shown superiority over other balanced approaches at equal calories, but the structure helps some people maintain consistency. Our Zone preset implements this 40/30/30 ratio if you want to try this structured approach to balanced eating.

Meal frequency is largely personal preference—total daily intake matters more than timing for most goals. Research shows: 3-6 MEALS are all viable for weight management. The 'eat 6 small meals to boost metabolism' myth has been debunked—thermic effect is the same whether you eat 3 or 6 meals of equivalent total calories. FOR MUSCLE BUILDING: Spreading protein across 3-5 meals (20-40g each) may slightly optimize muscle protein synthesis compared to one or two large servings. FOR SATIETY: Some people do better with fewer, larger meals; others prefer more frequent eating. Experiment to find what helps you adhere to your calorie/macro targets. Our calculator lets you choose 3-6 meals and calculates per-meal targets to help with meal prepping.

Fiber is a crucial but often overlooked nutrient—a type of carbohydrate your body can't digest. Benefits include: SATIETY: Fiber adds bulk to food, helping you feel full on fewer calories—crucial for fat loss. GUT HEALTH: Feeds beneficial gut bacteria. BLOOD SUGAR: Slows digestion, preventing blood sugar spikes. HEART HEALTH: Soluble fiber can reduce cholesterol. REGULARITY: Prevents constipation. RECOMMENDATIONS: 14g per 1,000 calories consumed, or approximately 25-38g per day for adults. Most people consume only 15g or less. Sources: vegetables, fruits, legumes, whole grains, nuts, seeds. Our calculator provides a fiber recommendation based on your calorie target. Increase fiber gradually to avoid digestive discomfort and drink adequate water.

Water needs vary by body size, activity level, climate, and diet. General guidelines: BASELINE: About 35ml per kg of bodyweight, or roughly 0.5oz per pound. For a 70kg (154 lb) person, that's about 2.5 liters (84 oz). ACTIVE PEOPLE: Add 500-1000ml for each hour of exercise. HIGH PROTEIN DIETS: May require slightly more water for kidney function. PRACTICAL SIGNS OF HYDRATION: Urine should be pale yellow (not clear or dark). Thirst is a late indicator—if you're thirsty, you're already mildly dehydrated. Water supports every metabolic process, exercise performance, satiety (people often confuse thirst for hunger), and nutrient transport. Our calculator provides a personalized water recommendation based on your body weight.

Several factors could explain a stalled scale despite a calculated deficit: (1) UNDERESTIMATING INTAKE: Food logging errors are common—oils, sauces, beverages, bites add up. Weighing food is more accurate than volume measures. (2) OVERESTIMATING ACTIVITY: TDEE calculators estimate average burns; your actual expenditure may be lower. (3) METABOLIC ADAPTATION: After prolonged dieting, BMR can decrease 10-15% beyond what weight loss alone would predict. (4) WATER RETENTION: Stress, high sodium, new exercise, menstrual cycle can mask fat loss with water weight. (5) WEEKENDS/CHEAT MEALS: Two high-calorie days can eliminate a week's deficit. (6) YOU'RE ACTUALLY LOSING FAT: If lifting weights, you may be gaining muscle while losing fat (body recomposition). Measurements and photos may show progress the scale doesn't. Solution: Track everything meticulously for 2 weeks, reassess TDEE, or reduce intake by another 200-300 calories.

Reverse dieting is the strategic process of slowly increasing calories after a prolonged diet to restore metabolism and prevent rapid fat gain. After dieting, your metabolism is suppressed and hormones (leptin, thyroid) are down-regulated. Jumping straight to maintenance or surplus often causes rapid fat regain. THE PROCESS: Add 50-100 calories per week (primarily from carbs/fats, protein stays constant) until reaching estimated TDEE. This may take 4-12 weeks depending on how aggressive the diet was. BENEFITS: Minimizes fat regain, restores hormonal function, increases energy and workout performance, psychologically easier than staying in prolonged restriction. WHEN TO USE: After any diet lasting 8+ weeks, after competition/photoshoot prep, or when diet fatigue becomes unbearable. Our calculator can help you set increasing calorie targets as you reverse.

No. This macro calculator runs entirely in your browser. Your age, weight, body fat, and calculated nutrition data are processed locally on your device and are never sent to our servers or stored anywhere. When you close or refresh the page, all data is cleared. Your nutrition information stays completely private.