Macro Calculator (Protein, Carbs, Fat in Grams)
Splits your daily calorie target by your chosen protein and fat shares and converts protein, carbohydrate and fat into grams and calories.
Things to keep in mind:
- With kidney disease, diabetes, pregnancy or breastfeeding the macro split should be set by a physician or dietitian.
- Because label energy values are rounded and fibre provides less energy, actual intake can differ slightly from the calculation.
- This tool is not a meal plan or medical advice; it gives an estimated split.
Calculator
Result
Enter the values and press Calculate to see the result here.
About this tool
Macronutrients are the three energy-providing nutrient groups: protein, carbohydrate and fat. Even when you know your calorie target, the answer to "how many grams of protein should I eat?" depends on how you split those calories between the macros. This tool divides your daily calories by the percentages you choose and converts each macro into grams. The carbohydrate share is derived automatically as what remains after protein and fat, so the shares always add up to 100%.
Formulas (Atwater energy factors)
- Carbohydrate (%) = 100 − protein (%) − fat (%)
- Macro calories = daily calories × macro share ÷ 100
- Protein (g) = protein calories ÷ 4 (1 g protein ≈ 4 kcal)
- Carbohydrate (g) = carbohydrate calories ÷ 4 (1 g carbohydrate ≈ 4 kcal)
- Fat (g) = fat calories ÷ 9 (1 g fat ≈ 9 kcal)
- Protein per kilogram = protein (g) ÷ body weight (kg)
Example
2,000 kcal per day, 30% protein, 30% fat → 40% carbohydrate.
- Protein: 2,000 × 0.30 = 600 kcal ÷ 4 = 150 g
- Carbohydrate: 2,000 × 0.40 = 800 kcal ÷ 4 = 200 g
- Fat: 2,000 × 0.30 = 600 kcal ÷ 9 = 66.7 g For a 70 kg person this is 2.14 g of protein per kilogram.
How to read the result
Widely accepted ranges for healthy adults are roughly 45–65% of energy from carbohydrate, 20–35% from fat and 10–35% from protein. For people who train, protein needs are usually expressed as 1.2–2.0 g per kilogram. It is best to find your daily calorie need with the BMR calculator first and enter it here.
How to use
- Enter your daily calorie target (use the daily calorie calculator first if you do not know it).
- Enter the share of calories from protein and from fat; carbohydrate is the remaining share.
- Optionally enter your weight to see protein per kilogram.
- Split the gram amounts across your meals to build your plan.
Notes
General Atwater factors are used: protein and carbohydrate 4 kcal/g, fat 9 kcal/g. Grams are rounded half-up to 1 decimal, calories to whole numbers and protein per kilogram to 2 decimals. Alcohol (7 kcal/g) and fibre are not included.
Sources
References
- [1]Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino AcidsInstitute of Medicine / National Academies Press, 2005
Frequently asked questions
A commonly used minimum for sedentary adults is about 0.8 g per kilogram; for people who train regularly 1.2–2.0 g/kg is recommended. Enter your weight here to see how many grams per kilogram your chosen split provides.
Generally accepted ranges for healthy adults are carbohydrate 45–65%, fat 20–35% and protein 10–35%. Protein is usually increased during weight loss, while endurance athletes use more carbohydrate.
These are the general Atwater energy factors: in the body 1 gram of fat provides about 9 kcal and 1 gram of protein or carbohydrate about 4 kcal. Food label energy values are calculated with the same factors.
The three shares must always add up to 100%. To prevent wrong totals you enter protein and fat; carbohydrate is calculated automatically as the remaining share and shown in the result.
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