Protein and carbohydrate supply 4 kcal per gram and fat supplies 9 kcal per gram, which is how percentages turn into grams.
How to use the Macro Calculator
- Daily calories
- Protein
- Carbohydrate
- Fat
Results update as you type, and every field accepts the units shown in its menu.
How it works
Multiply your calories by each percentage and divide by the calories per gram for that nutrient.
Inputs explained
| Field | What to enter |
|---|---|
| Daily calories | In kcal |
| Protein | In % |
| Carbohydrate | In % |
| Fat | In % |
What each result means
- Protein = [Daily calories]×[Protein]÷100÷4
- Carbohydrate = [Daily calories]×[Carbohydrate]÷100÷4
- Fat = [Daily calories]×[Fat]÷100÷9
- Percentages total = [Protein] + [Carbohydrate] + [Fat]
Example values
How the main result changes when Daily calories changes and everything else stays at the example values above:
| Daily calories (kcal) | Protein (g) |
|---|---|
| 1,100 | 83 |
| 1,650 | 124 |
| 2,200 | 165 |
| 2,750 | 206 |
| 3,300 | 248 |
| 4,400 | 330 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
Protein g = kcal × P% ÷ 4Carbs g = kcal × C% ÷ 4Fat g = kcal × F% ÷ 9Worked example
Inputs — Daily calories: 2,200 kcal; Protein: 30 %; Carbohydrate: 40 %; Fat: 30 %.
Results — Protein = 165 g; Carbohydrate = 220 g; Fat = 73 g; Percentages total = 100 %.
Key terms
- Macronutrients
- Protein, carbohydrate and fat.
Frequently asked questions
What split should I use?
Dietary guidelines suggest 45–65% carbs, 20–35% fat and 10–35% protein for adults.
Does alcohol count?
Alcohol has 7 kcal/g and is not included here.
What formula does the Macro Calculator use?
Protein g = kcal × P% ÷ 4.