Macro Calculator

Understanding Macronutrient Targets

Macronutrients are the three main sources of energy in the diet: carbohydrates, protein, and fats. This calculator starts with an estimated calorie target, then distributes those calories into macro grams for your selected goal.

Common macronutrient ranges (AMDR)

Public health guidelines often reference the Acceptable Macronutrient Distribution Ranges (AMDR) for adults:

• Carbohydrate: 45-65% of total calories
• Fat: 20-35% of total calories
• Protein: 10-35% of total calories

Calories per gram

• Carbohydrates: 4 kcal per gram
• Protein: 4 kcal per gram
• Fat: 9 kcal per gram

How this calculator sets your split

For maintenance, it uses a balanced split. For fat loss, protein is slightly higher to support lean mass while calories are reduced. For muscle gain, calories are modestly higher with a bit more carbohydrate to support training.

Important limitations

• Macro needs vary with training volume, body composition, and personal preference.
• People with medical conditions, pregnancy, or special diets should seek professional advice.
• These targets are a starting point, not a medical or nutrition prescription.

Sources

• National Academies Press: Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
• NIH NIDDK: Body Weight Planner (energy balance overview)