Macro Calculator

What are macronutrients?

In health and fitness, macronutrients are the compounds eaten in large quantities that provide the body's bulk energy: carbohydrates, proteins, and fats — the three this calculator covers. (Some definitions add water and certain minerals, which are also needed in quantity.) Micronutrients are the other essential half of nutrition: vitamins and dietary minerals such as vitamin A, copper, iron, and iodine, needed at under 100 milligrams a day, against grams per day for macros.

Protein is built from amino acids, some of which — the essential amino acids — can only come from food. Sources span animal (meat, dairy) and plant (beans, legumes, nuts, seeds) foods, plus supplements. Healthier picks include soy, beans, nuts, fish, skinless poultry, lean beef, pork, and low-fat dairy; the unhealthier end is fried and processed meats (deli meats, sausages, fast-food burgers), high-sugar yogurts, processed protein bars, and many cheeses. Carbohydrates are classified as sugar (the simplest form), starch, and fiber, and by their saccharide count — monosaccharides and disaccharides ("simple") versus oligosaccharides and polysaccharides ("complex"). Glucose is a key monosaccharide fuel; polysaccharides like cellulose can't be digested for energy but supply valuable fiber. Sugar-heavy processed carbs are the problem end; complex carbs from vegetables, fruit, whole grains, and legumes are beneficial and necessary. Fat — cholesterol, phospholipids, triglycerides — has structural and metabolic roles and is the most energy-dense storage form. Saturated and trans fats are the unhealthy classes; monounsaturated, polyunsaturated, and omega-3 fats are the better sources. US dietary guidance: avoid trans fats where possible, keep saturated fat under 10% of daily calories, and replace saturated with mono- and polyunsaturated fats.

Daily calorie needs

Everything starts from daily energy need, driven by height, weight, age, activity, and whether the goal is to maintain, lose, or gain. This calculator estimates resting expenditure with one of two equations — Mifflin St Jeor (from weight, height, age, and sex) or Katch-McArdle (from lean body mass, so it can be more accurate for lean people who know their body fat percentage) — then applies the activity factor and the goal adjustment. Across the population, needs run roughly 1,600–3,000 Calories a day: generally 2,000–3,000 for men and 1,600–2,400 for women, rising with activity. Since protein, carbs, and fat supply nearly all of that energy, their gram targets follow directly once the calorie target is set — using the standards of bodies such as the American Dietetic Association, the CDC, and the WHO.

Macronutrients in common foods