Macro Calculator (Protein, Carbs, Fat)

About the Macro Calculator (Protein, Carbs, Fat)

Macronutrients are the parts of food that provide energy: protein and carbohydrate (about 4 kcal per gram) and fat (about 9 kcal per gram), plus alcohol (about 7). Once you know how many calories you need, splitting them into grams makes them practical — "about 110 g of protein a day, or 37 g a meal" is easier to plan than "22% of energy".

Choose a preset — balanced, high protein, low carb, keto or endurance — or set your own protein (in g per kg of body weight or as a percentage) and fat. You get grams per day and per meal, the share of calories, a fibre target of 14 g per 1,000 kcal, and a check against the US/Canadian Acceptable Macronutrient Distribution Ranges and the ICMR-NIN protein, oil and sugar guidance for India. The reverse mode turns grams from a food label or recipe into calories.

Acceptable Macronutrient Distribution Ranges (AMDR)

The US Institute of Medicine (now the National Academies) set ranges that keep the risk of chronic disease low while providing enough essential nutrients. For adults 19 and over:

• Carbohydrate: 45–65% of calories, and at least the RDA of 130 g a day
• Fat: 20–35% of calories
• Protein: 10–35% of calories, and at least the RDA of 0.8 g per kg of body weight
• Fibre: an adequate intake of 14 g per 1,000 kcal
• Added sugars: no more than 25% of calories

Children have different ranges (1–3 years: fat 30–40%, protein 5–20%; 4–18 years: fat 25–35%, protein 10–30%). Source: Health Canada’s DRI tables, which reproduce the joint US/Canadian values.

ICMR-NIN guidance for India

• Protein: the RDA for Indian adults is 0.83 g per kg a day (the average requirement is 0.66 g/kg). If your diet is mostly cereals with lower-quality protein, ICMR-NIN suggests 1 g per kg, and a cereal : pulse : milk ratio of about 3 : 1 : 2.5 to improve protein quality.
• Visible fat (cooking oil, ghee, butter): 20–50 g a day depending on your energy needs — no more than 27 g for a 2,000 kcal diet. This counts only fat you add, not the fat already in foods.
• Sugar: the 2024 Dietary Guidelines for Indians advise less than 5% of total energy from sugar for adults — 25 g a day on 2,000 kcal.

Sources: ICMR-NIN Nutrient Requirements for Indians, 2020 (brief note) and Dietary Guidelines for Indians, 2024.

How the presets are defined

• Balanced — 50% carbohydrate, 30% fat, 20% protein: inside every AMDR and the ISSN “normal diet” for general fitness (45–55% carbohydrate, 15–20% protein, 25–35% fat).
• High protein — 1.6 g/kg, the middle of the 1.4–2.0 g/kg that the ISSN position stand on protein finds sufficient for most exercising people; fat 30%; carbohydrate the rest.
• Low carb — carbohydrate 30% of calories, within the 26–45% that the American Diabetes Association consensus report calls a low-carbohydrate eating pattern; protein 25%; fat the rest.
• Keto — 40 g of carbohydrate a day, within the 20–50 g of non-fibre carbohydrate the ADA report says very-low-carbohydrate plans often use to induce ketosis; protein 20%; fat the rest.
• Endurance — carbohydrate 6 g/kg (ISSN: 5–8 g/kg for 2–3 hours of intense training on most days; 8–10 g/kg for 3–6 hours) and protein 1.6 g/kg; fat the rest.

Low-carb and keto plans fall outside the AMDR for fat and carbohydrate by design — the calculator tells you when that happens.

From grams to calories

Energy = 4 × protein + 4 × carbohydrate + 9 × fat + 7 × alcohol + 2 × fibre (kcal, grams). These are the Atwater general factors from FAO’s 2003 report on food energy — 17, 17, 37, 29 and 8 kJ per gram. Enter carbohydrate and fibre separately: if your label’s carbohydrate figure includes fibre (US labels show “total carbohydrate”, which does), subtract the fibre first. 1 kcal = 4.184 kJ.

Limitations

• The AMDR and presets are for healthy adults. Children, pregnancy, kidney disease, diabetes and other conditions need individual advice.
• Calorie estimates from the built-in Mifflin-St Jeor × activity formula are approximate; see the TDEE calculator for two methods side by side.
• Grams are of the nutrient, not of food: 100 g of protein is not 100 g of chicken or paneer — check the nutrition label or a food composition table.
• Atwater factors are averages; the true energy you absorb from a particular food can differ slightly.

Privacy

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