Calculate your ideal daily macros — protein, carbs, and fat — for weight loss, muscle gain, or maintenance. This macro calculator supports keto macros, low-carb, balanced, and high-protein splits with your exact calorie and protein carbs fat ratio.
Protein, carbs & fat for your goal
Macronutrients — protein, carbohydrates, and fat — are the three main calorie-providing nutrients, and tracking them gives you precise control over your body composition. Protein provides 4 calories per gram and drives muscle repair and satiety. Carbohydrates also provide 4 cal/g and are the body's preferred fuel for exercise and brain function. Fat provides 9 cal/g and is essential for hormone production, vitamin absorption, and cell membrane integrity. The ideal protein carbs fat ratio depends on your goal: a balanced 30/40/30 split works well for maintenance and general health, while keto macros (25/5/70) restrict carbs dramatically to put the body in a fat-burning ketosis state. High-protein splits like 40/35/25 are popular for fat loss because protein is the most satiating macro — it reduces hunger without inflating calories.
Most Americans eat far too little protein and rely too heavily on refined carbohydrates, which spike blood sugar and drive fat storage. The USDA Dietary Guidelines suggest 10–35% of calories from protein, but research consistently shows that 25–35% is more effective for body composition improvement. For a 170-pound person eating 2,200 calories/day, that means roughly 138–193 grams of protein daily. The keto diet has surged in popularity — US Google searches for "keto macros" peak every January — but it requires strict adherence to under 20–50g of net carbs per day. Use this macro calculator to find your starting targets, then adjust based on 4-week results in the mirror and on the scale.
Aim for 0.7–1g per pound of body weight for muscle retention during fat loss, or 1–1.2g/lb for active muscle building. At 180 lbs, that's 126–216g of protein daily — spread across 4–5 meals for best absorption and satiety.
The body's preferred energy source for high-intensity exercise. Athletes and endurance runners benefit from 45–55% of calories from carbs. For keto, cut to under 50g of net carbs per day to enter ketosis — typically within 2–7 days for most people.
Essential for testosterone, estrogen, and cortisol production — don't drop below 0.3g per pound of body weight. Prioritize unsaturated fats from olive oil, avocados, and nuts over saturated fat from processed foods.
MyFitnessPal, Cronometer, and Lose It are the most popular free macro tracking apps in the US. All three let you log food by barcode scan and compare your daily intake to your protein, carbs, and fat targets in real time.
Macronutrient targets divide a calorie budget between protein, carbohydrate and fat, each carrying a different energy density: protein and carbohydrate supply 4 calories per gram, fat 9. The sensible order of decisions is to fix protein first from body weight rather than from a percentage, since its requirement scales with lean mass and training rather than with total intake. Fat is then set to a minimum for hormonal function — roughly 0.6 g per kilogram — and carbohydrate simply fills whatever remains. Percentage-first splits invert this and can leave protein badly short at low calorie intakes.
Protein g = calories × protein% ÷ 4 (or body weight × 1.6–2.2 g/kg)Carbohydrate g = calories × carb% ÷ 4Fat g = calories × fat% ÷ 9Check: (P × 4) + (C × 4) + (F × 9) = total calorieswhere:
Assumptions: Ratios are a starting point, not a prescription. Total calories determine weight change; macro split influences body composition, satiety and training performance. Medical conditions such as diabetes or kidney disease require individualised targets.
Convert a calorie target and percentage split into grams, then sanity-check the protein.
Result165 g protein · 220 g carbohydrate · 73 g fat
The cross-checks are the useful part. At 1,600 calories the same 30% split would give only 120 g of protein — 1.46 g/kg, below the range for someone training in a deficit. That is why protein should be fixed in grams first and the percentages allowed to follow.