Macros (macronutrients) are the nutrients that supply nearly all of your food energy: protein, carbohydrates, and fat. This calculator estimates how many grams of each to eat per day from your calorie target and a chosen split (Balanced, Low Fat, Low Carb, High Protein, or custom).

How are daily calories calculated?

First estimate basal metabolic rate (BMR) with Mifflin St Jeor (age, sex, height, weight) or Katch-McArdle (lean mass from body fat %). Multiply by an activity factor, then add or subtract 250, 500, or 1,000 calories for a mild, standard, or extreme weight-change goal. The result is rounded to a whole calorie.

Why aren't protein and carbs 4 kcal/g and fat 9 kcal/g?

The calculator now uses the standard food-label factors: 4 calories per gram of protein, 4 per gram of carbohydrate, and 9 per gram of fat.

What do the protein, carb, and fat ranges mean?

The highlighted grams are the selected plan. The ranges are guideline bands use the adult Acceptable Macronutrient Distribution Ranges: protein 10–35%, carbohydrate 45–65%, and fat 20–35% of calories. The added-sugar and saturated-fat figures each use 10% of calories as a planning limit.

Which macro plan should I use?

Balanced (25/50/25) is a solid default for most people. Low Fat raises carbs and protein slightly. Low Carb is 30/40/30. High Protein is 35/42.5/22.5. Create Your Own lets you type any three percentages that add to 100%. Athletes, pregnancy, and medical diets need a clinician's advice — these figures are typical-situation estimates.

Macro Calculator — Protein, Carbs & Fat (Daily Grams)

Estimate how many grams of protein, carbohydrates, and fat to eat each day from your age, sex, height, weight, activity, and goal. Switch US and metric units, pick a plan (Balanced, Low Fat, Low Carb, High Protein, or a custom split), and see calories, kilojoules, guideline ranges, plus sugar and saturated-fat limits.

What are macronutrients?

Protein, carbohydrate, and fat are the bulk energy nutrients. Protein supplies essential amino acids (from meat, dairy, beans, nuts, and seeds). Carbohydrates cover sugars, starches, and fiber; complex sources (vegetables, fruit, whole grains, legumes) are the usual priority over added sugar. Fat is the densest energy store and is needed for cell membranes and fat-soluble vitamins — unsaturated fats are generally preferred, trans fats avoided, and saturated fat kept under about 10% of calories in U.S. dietary guidance.

Micronutrients (vitamins and minerals) matter too, but they are needed in milligrams, not tens of grams, and are not totaled here.

Macronutrients in common foods

Food	Serving	Protein	Carbs	Fat
Apple	1 (4 oz.)	0.3 g	14.4 g	0.2 g
Banana	1 (6 oz.)	1.9 g	38.9 g	0.6 g
Broccoli	1 cup	2.6 g	6.0 g	0.3 g
Chicken, cooked	2 oz.	16 g	0 g	1.8 g
Egg	1 large	6.3 g	0.4 g	5.0 g
Rice, cooked	1 cup	4.2 g	44.1 g	0.4 g
Milk (2%)	1 cup	8.1 g	11.4 g	4.8 g
Greek yogurt (low-fat)	1 cup	12.9 g	17.3 g	3.8 g

Examples

Man, 25, 5 ft 10 in, 165 lb, moderate, maintain

Mifflin St Jeor at moderate activity (1.465) is 2,549 Calories/day (10,665 kJ). Balanced macros are 159 g protein, 319 g carbs, 71 g fat, with ranges 64–223 / 287–414 / 57–99 g, added sugar under 64 g, and saturated fat under 28 g. Low Fat is 175/335/57, Low Carb 191/255/85, and High Protein 223/271/64.

Woman, 30, 5 ft 4 in, 140 lb, light activity, mild loss

Female Mifflin at light activity (1.375) minus 250 calories is 1,593 Calories/day (6,665 kJ). Balanced macros are 100 g protein, 199 g carbs, 44 g fat.

Metric default, 180 cm, 65 kg

The same age-25 male at moderate activity in metric units is 2,425 Calories/day, Balanced 152 / 303 / 67 g.

Formula

Calories start with basal metabolic rate (BMR), then activity and a weight goal. Mifflin St Jeor (the default) uses kilograms (W), centimetres (H), and years (A). Katch-McArdle uses lean mass from body-fat fraction (bf):

Men:     BMR = 10W + 6.25H − 5A + 5
Women:   BMR = 10W + 6.25H − 5A − 161
Katch:   BMR = 370 + 21.6 × W × (1 − bf)
Calories = round(BMR × activity + goal)
kJ       = round(calories × 4.184)

Goal adjustments assume about 3,500 calories per pound: 0 (maintain), ±250 (0.5 lb / 0.25 kg per week), ±500 (1 lb / 0.5 kg), ±1,000 (2 lb / 1 kg).

Each plan assigns a percentage of those calories to protein, carbs, and fat. Grams are round(calorie share ÷ kcal per gram) with 4 / 4 / 9 kcal/g.

Plan	Protein	Carbs	Fat
Balanced	25%	50%	25%
Low Fat	27.5%	52.5%	20%
Low Carb	30%	40%	30%
High Protein	35%	42.5%	22.5%

Activity level	Factor
Basal Metabolic Rate (BMR)	1.0
Sedentary (little or no exercise)	1.2
Light (1–3 times/week)	1.375
Moderate (4–5 times/week)	1.465
Active (daily, or intense 3–4 times/week)	1.55
Very Active (intense 6–7 times/week)	1.725
Extra Active (very intense daily, or physical job)	1.9

The displayed ranges convert the adult AMDR percentages to grams. Added sugar and saturated fat limits each convert 10% of calories to grams.

These numbers are typical-situation estimates. If you are an athlete, pregnant, or on a medical diet, ask a doctor or registered dietitian before changing how you eat. Very low calorie intakes should only be used under medical supervision.

Exercise here means 15–30 minutes of elevated heart rate. Intense exercise is 45–120 minutes; very intense is 2+ hours.

Sources

FDA Food Labeling Guide — 4/4/9 calorie-per-gram label factors.
USDA National Agricultural Library: Macronutrients — gateway to the National Academies Dietary Reference Intake report and adult distribution ranges.
Mifflin et al. (1990) — resting-energy equation.

Macro Calculator

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