VitalMetrics

Macro Calculator

Turn a calorie target into daily grams of protein, carbohydrate and fat. Start from a preset or set the split yourself.

Units
Sex
ft
in
lb
1,892kcal/day
Protein
118 g
Carbohydrate
236 g
Fat
53 g

Protein = 1.7 g per kg body weight. This split sits inside the AMDR ranges.

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How the macro calculator works

First it estimates your daily calories (Mifflin-St Jeor × activity, plus your goal adjustment). Then each macro gets its share: grams = calories × percent ÷ kcal per gram, using 4 kcal/g for protein and carbohydrate and 9 kcal/g for fat. For 2,000 kcal at 25/50/25: 125 g protein, 250 g carbs, 56 g fat.

Picking a split

  • Balanced (25/50/25): close to typical dietary guidelines; easy to follow with ordinary meals.
  • Higher protein (30/40/30): popular when losing weight, because protein is filling and helps hold on to muscle.
  • Lower carb (30/30/40): below the 45% AMDR floor for carbs; some people prefer it, but ask a clinician first if you have diabetes or take glucose-lowering medicine.
  • Endurance (20/60/20): more carbohydrate for long training sessions.

Whatever split you choose, fibre (25 g a day for women, 38 g for men, per the National Academies) and food quality matter as much as the percentages.

Questions people ask

What are macros?

Macronutrients are the three nutrients that provide calories: protein and carbohydrate at about 4 kcal per gram, and fat at about 9 kcal per gram. Alcohol adds 7 kcal per gram but isn’t counted as a nutrient.

What is a good macro split?

The US National Academies’ Acceptable Macronutrient Distribution Ranges for adults are 45–65% of calories from carbohydrate, 20–35% from fat and 10–35% from protein. Many balanced diets sit around 25/50/25.

How do I calculate macros for weight loss?

Set a calorie target below maintenance with the calorie calculator, keep protein relatively high (often 1.2–1.6 g per kg) to protect muscle, then divide the remaining calories between carbs and fat to taste.

Do I have to hit my macros exactly?

No. Treat the grams as a weekly average. Getting total calories, enough protein and plenty of fibre-rich foods right matters more than a perfect split each day.

Sources

  1. Institute of Medicine (2005). Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids: AMDR ranges.
  2. USDA / HHS. Dietary Guidelines for Americans 2020–2025.
  3. Atwater factors. 4 kcal/g protein and carbohydrate, 9 kcal/g fat (USDA).

Every formula on VitalMetrics is listed with its original reference on Sources & methods.

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