Macro Calculator
Split your daily calories into grams of protein, carbohydrates and fat for balanced, low-carb, high-protein or keto diets.
What are macros?
Macronutrients are the three nutrients that provide calories: protein, carbohydrate and fat. Each supplies a fixed amount of energy per gram:
- Protein: 4 kcal per gram. Builds and repairs muscle, keeps you full.
- Carbohydrate: 4 kcal per gram. The main fuel for intense exercise and the brain.
- Fat: 9 kcal per gram. Needed for hormones and absorbing vitamins A, D, E and K.
Grams = Calories × macro% ÷ kcal per gram
On 2,200 kcal with a balanced 50/20/30 split: carbs 1,100 kcal ÷ 4 = 275 g, protein 440 ÷ 4 = 110 g, fat 660 ÷ 9 = 73 g.
Choosing a split
The US Dietary Guidelines suggest 45–65% of calories from carbs, 10–35% from protein and 20–35% from fat. Within those ranges, the best split is the one you can stick to. Research comparing low-fat and low-carb diets finds similar weight loss when calories are equal.
- Losing fat or building muscle: aim for 1.6–2.2 g of protein per kg of body weight (0.7–1 g per lb). The high-protein split usually gets you there.
- Endurance sports: more carbohydrate, often 50–60% of calories.
- Keto: under about 50 g of carbs a day to stay in ketosis. Talk to a doctor first if you have diabetes or take medication.
Frequently asked questions
How much protein do I need per day?
The minimum for adults is 0.8 g per kg of body weight. People who train or are losing weight benefit from 1.6–2.2 g per kg.
Do macros matter if I hit my calories?
Calories mainly determine weight change, but macros affect body composition, fullness and performance. Enough protein helps you keep muscle while losing fat.
How many carbs are allowed on keto?
Most keto plans keep net carbohydrates below 20–50 g a day, which is about 5–10% of calories.
Last reviewed Oct 20, 2026. Results are estimates; check important decisions with a qualified professional.