Macro Calculator
Determine your optimal macronutrient breakdown based on your calorie target and diet preference. Choose from balanced, low-carb, high-protein, or keto ratios to see daily gram targets for protein, carbohydrates, and fat.
Macros — short for macronutrients — are the three food categories your body needs in large quantities: protein, carbohydrates, and fat. Together they make up the calorie content of food (4 cal/g for protein and carbs, 9 cal/g for fat). The ratio between them changes how your body responds to a given calorie intake, especially under deliberate calorie surplus or deficit.
This calculator splits your daily calorie target into grams of protein, carbs, and fat based on a chosen ratio: balanced (30/40/30), low-carb (40/25/35), high-protein (40/30/30), zone (30/40/30), or low-fat (30/50/20). The first percentage is protein, the second carbs, the third fat.
For most people, the most impactful macro decision is hitting an adequate protein target — typically 0.7–1.0 g per pound of body weight, especially during a calorie deficit or active muscle-building phase. Protein has the highest thermic effect (~25% burned during digestion), preserves muscle during dieting, and produces the strongest satiety signal. After protein is set, the carb-fat split is largely a matter of preference and what supports adherence.
Inputs
Results
Protein
150g
30% (600 cal)
Carbs
200g
40% (800 cal)
Fat
67g
30% (600 cal)
Diet Type
Balanced
Macro Breakdown
Formula
How to use this calculator
- Enter your daily calorie target (use TDEE or calorie calculator if you need to find it first).
- Choose a diet style. For weight loss with muscle retention, "High Protein" works well. For endurance athletes, "Balanced." For low-carb approaches, "Low Carb."
- Read the gram targets. Plan meals to hit each within ~10% — exact precision daily isn't needed.
- Hit protein first, then fill remaining calories with carbs and fat in your chosen ratio.
- Track for 1–2 weeks with an app (Cronometer, MyFitnessPal) to learn what your typical meals contribute.
Worked examples
Weight loss with muscle retention
170 lb person at 1,800 cal (deficit), high-protein ratio. Protein: (1800 × 0.40) / 4 = 180 g (about 1 g/lb) Carbs: (1800 × 0.30) / 4 = 135 g Fat: (1800 × 0.30) / 9 = 60 g The high protein intake (~1g/lb) preserves muscle during the cut. Carbs around the workout window; fat distributed across other meals.
Keto-leaning low-carb
Same person, same calories, but Low Carb ratio (40/25/35): Protein: 180 g Carbs: 113 g Fat: 70 g Strict keto would push fat to 60%+ of calories and carbs under 50g/day, but moderate low-carb is much more sustainable for most people.
When to use this calculator
Use this when: - Starting a deliberate diet or fitness phase - Adjusting macros after a body recomposition plateau - Planning meals for the week - Validating that current intake matches goals
Two related calculators help: TDEE for the calorie target, and the protein calculator for a deeper look at protein needs by activity level. For people focused on body recomposition, the priority is hitting protein and total calories; the carb-fat ratio is largely about adherence and energy levels during training.
This isn't medical nutrition advice. People with kidney disease, eating disorders, or specific medical conditions should consult a registered dietitian or physician for personalized recommendations.
Common mistakes to avoid
- Obsessing over exact grams. Real-world tracking accuracy is ±5–10%; close-enough beats perfectionism.
- Hitting calorie targets without protein focus. Under-protein during a deficit leads to muscle loss.
- Demonizing macronutrients. Carbs aren't bad. Fat isn't bad. The diet that works is the one you can stick with.
- Switching ratios constantly. Pick one and follow it for 6+ weeks before changing.
- Counting alcohol toward macros. Alcohol has 7 cal/g and gets metabolized differently — most trackers treat it as a separate category.
- Ignoring fiber. Aim for 25–35g/day; it doesn't fit the macro split cleanly but matters for digestion and satiety.
Frequently Asked Questions
Sources & further reading
- Dietary Reference Intakes — Macronutrients — National Academies of Sciences, Engineering, and Medicine
- Protein intake and athletic performance — Journal of the International Society of Sports Nutrition