Macro Calculator
Adjust the inputs below. Results update as you type.
How it works
Typical macro splits: weight loss: 40% carb / 30% protein / 30% fat; muscle gain: 40–50% carb / 25–35% protein / 20–30% fat; keto: 5% carb / 25% protein / 70% fat. Protein: 4 kcal/g; carbs: 4 kcal/g; fat: 9 kcal/g. For muscle building, target 0.7–1g protein per lb of bodyweight. Track with a food diary app for accuracy—labels have up to 20% legal error.
Input guidance
- Use measured values (recent weight, height, activity level) rather than guesses.
- Recalculate every few weeks as your routine and body metrics change.
- Pair screening metrics with context such as sleep, stress, and medical history.
The formula
Split total calories into protein, carbs, and fat. Protein and carbs are 4 calories per gram, fat is 9. A common split is 30% protein, 40% carbs, 30% fat, adjusted to goals.
Worked example
On 2,000 calories with 30/40/30: protein = 600 cal ÷ 4 = 150 g, carbs = 800 ÷ 4 = 200 g, fat = 600 ÷ 9 = 67 g.
More examples to test
- Maintenance case: keep activity constant and observe expected baseline ranges.
- Adjustment case: change only one major variable to understand sensitivity.
How to interpret results
Use results for awareness and planning, then validate with qualified medical or nutrition professionals for individualized decisions.
When this can be inaccurate
Population formulas cannot account for all biological factors such as medical conditions, medication effects, body composition differences, and genetics.
Change history
- July 2026: Quality-reviewed for publication with formula checks and explanatory copy updates.
Site-wide corrections also appear on the corrections log.
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General wellness resource.
Frequently asked questions
What are macros?+
Macronutrients — protein, carbohydrate, and fat — the three energy-providing nutrients. Hitting target grams of each supports specific fitness goals.
How much protein do I need?+
Active people often aim for roughly 0.7–1 g per pound of body weight to preserve muscle, especially in a calorie deficit.
Do macros matter more than calories?+
Total calories drive weight change; macros shape body composition, energy, and satiety. Both matter for results you can sustain.
Can this calculator diagnose a condition?+
No. It is a screening and education tool only, not a clinical diagnosis.
When should I seek professional advice?+
Seek professional advice when results are extreme, persistent, or conflict with symptoms, goals, or prior medical guidance.
Guided next steps
Want the full workflow? Use this calculator inside a step-by-step guide.