Macro Calculator

What your macros mean

The calories are your daily target; the three gram numbers split it between protein, fat and carbohydrate. Hit the calories and the protein first: they matter most for body weight and muscle. Fat and carbs can trade places a little from day to day.

The four goals are our choices, placed inside ranges from published sources: protein from the ISSN position stand (1.4 to 2.0 g/kg for people who exercise), fat and carbs checked against Health Canada's acceptable ranges for adults (protein 10 to 35%, fat 20 to 35%, carbs 45 to 65% of calories). If a split falls outside those ranges, the result says so.

• Maintain: maintenance calories, protein 1.6 g/kg, fat 30%, carbs the rest.
• Lose fat: 20% under maintenance, protein 2.0 g/kg, fat 30%, carbs the rest.
• Gain muscle: 10% over maintenance, protein 1.6 g/kg, fat 25%, carbs the rest.
• Keto: maintenance calories, protein 1.6 g/kg, carbs 30 g, fat the rest.

The formula

Calories = TDEE × goal factor
Protein (g) = weight (kg) × g/kg
Fat (g) = calories × fat % / 9
Carbs (g) = (calories − 4 × protein
            − 9 × fat) / 4
Keto: carbs = 30 g, fat = the rest

TDEE is the Mifflin-St Jeor BMR times your activity factor, as in our TDEE calculator. The 4, 9 and 4 kcal per gram are the general Atwater factors listed by the FAO.

Worked example in pounds

A 30-year-old man, 180 lb (81.6 kg), 5 ft 10 in, moderately active, goal maintain:

• Calories = TDEE = 2,763 kcal
• Protein = 81.6 × 1.6 = 131 g (523 kcal)
• Fat = 2,763 × 30% / 9 = 92 g
• Carbs = (2,763 − 523 − 829) / 4 = 353 g (51% of calories)

Worked example in kilograms

A 35-year-old woman, 65 kg, 165 cm, lightly active, goal lose fat:

• Calories = 1,850 × 0.8 = 1,480 kcal
• Protein = 65 × 2.0 = 130 g; fat = 49 g; carbs = 129 g
• Carbs come to 35% of calories, under Health Canada's 45% minimum, so the calculator flags it. Lowering protein toward 1.6 g/kg or using a smaller deficit brings carbs back up.