Macro Calculator
Macro calculator works out Daily calorie target and Protein from Daily calorie target, Daily calorie adjustment and Method. The default figures on this page give protein of 150.0 g; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
7 steps
- Calorie target = 2000 + 0 = 2000 kcal.
- Percentage split 30 / 40 / 30.
- Protein 150 g x 4 = 600 kcal.
- Carbohydrate 200 g x 4 = 800 kcal.
- Fat 66.7 g x 9 = 600 kcal.
- Shares of energy: 30% protein, 40% carbohydrate, 30% fat.
- Across 3 meals: 50 g protein, 66.7 g carbohydrate, 22.2 g fat per meal.
Distribution-range notestable
Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed
Keep this result
Save it, change one figure, then compare the two
The calculation stays free. Save this scenario, adjust one assumption, save that too, and put them side by side to see exactly what the change costs you. A free account keeps 5 scenarios and 2 comparisons; Personal makes both unlimited and adds exports and private links. Nothing is saved unless you press Save.
What the macro calculator calculates
Converts a daily calorie target into protein, carbohydrate and fat gram targets by percentage split, grams per kilogram of body mass, or a fixed carbohydrate cap.
How to use this macro calculator
Enter Daily calorie target, Daily calorie adjustment, Method and Protein. Daily calorie target updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Daily calorie target, Protein and Carbohydrate.
The method follows 21 CFR 101.9(c)(1)(i) - caloric values of 4, 4 and 9 kcal per gram for protein, carbohydrate and fat, Institute of Medicine, Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids - Acceptable Macronutrient Distribution Ranges, National Academies, Rethinking the Acceptable Macronutrient Distribution Range for the 21st Century, Jäger et al., International Society of Sports Nutrition position stand: protein and exercise (1.4-2.0 g/kg/day for active adults) and MyFitnessPal Help Center, default nutrition goals (50% carbohydrate / 20% protein / 30% fat).
2,000 kcal split 25 / 50 / 25 example
With Daily calorie target: 2000, Protein: 25, Carbohydrate: 50, Fat: 25, the calculator returns Protein: 125, Carbohydrate: 250, Fat: 55.6. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Daily calorie target, Protein and Carbohydrate. The inputs you can vary are Daily calorie target, Daily calorie adjustment, Method, Protein, Carbohydrate and Fat.
Understanding Daily calorie target, Protein and Carbohydrate
Macronutrient targets are general nutrition arithmetic, not medical or dietetic advice. Anyone who is pregnant, under 18, managing diabetes, kidney disease, an eating disorder or any other condition should have targets set by a registered dietitian or physician.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
How do I calculate my macros?
Converts a daily calorie target into protein, carbohydrate and fat gram targets by percentage split, grams per kilogram of body mass, or a fixed carbohydrate cap. Open “How this is worked out” beside the result to see each step for your own figures.
What is the 40-40-20 rule for macros?
On the figures this page opens with — daily calorie target 2,000 kcal, protein 25%, carbohydrate 50% and fat 25% — the protein is 150 g. No single number fits everyone: change any figure above and the answer updates as you type, with each step of the arithmetic beside it.
Which macro calculator is most accurate?
The macro calculator follows the stated method, but the result is only as reliable as Daily calorie target, Daily calorie adjustment, Method, Protein and Carbohydrate and the assumptions shown. Check the working and sources before relying on it for an important decision.
What is the best macro formula for weight loss?
It needs Daily calorie target, Daily calorie adjustment, Method, Protein, Carbohydrate and Fat. Nothing else is required, and the figures stay in your browser.
What information do I need for the macro calculator?
You need Daily calorie target, Daily calorie adjustment, Method, Protein, Carbohydrate, Fat, Body weight and Body weight unit. The page opens with default figures that give protein of 150.0 g, so you can see the scale before entering your own.
What does this macro calculator show?
It shows Daily calorie target, Protein, Carbohydrate, Net carbohydrate, Fat, Calories from protein, Calories from carbohydrate and Calories from fat, with the working and any warnings for your entries.