Nutrition & macros

Your complete nutrition blueprint.

Estimate your protein, carbs, and fat split from your body and activity — try the macro calculator on this page, then save your targets with a free account.

By Aziz Mezlini, PhD · Founder & Scientist, Carthalis · Updated 2026-05-25

Estimate your macro split

Pavlidou RMR + PAL on this page for TDEE, then AMDR-based protein, carb, and fat grams for your goal. MET-based depth unlocks in the app.

Your inputs

We don't store these values until you sign up.

Your result

Fill in your inputs to see your personalised result here. The calculator runs entirely on this page — no signup required to try.

Wellness education, not medical or nutrition advice.

Sign up to use the MET-based engine in the app, plus meal suggestions, planning, and logging tools aligned to your macro targets.

Save your result with a free account

Methodology

  • Pavlidou et al. 2023 — resting metabolic rate equation (Nutrients 15:1165)
  • FAO/WHO/UNU 2004 — physical activity level (PAL) multipliers
  • Dietary Guidelines for Americans 2020–2025 — AMDR macro ranges
  • Institute of Medicine 2002 — 0.8 g/kg/day protein RDA floor

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What this number actually measures

Macronutrients are the three main nutrients your body needs in large amounts. A macro split is an educational estimate of how daily calories distribute across protein, carbohydrates, and fats — based on your total daily energy needs and fitness goal, not a medical prescription.

  • Protein

    Building blocks for muscle repair and growth; also supports satiety and metabolism.

    Calories: 4 kcal/g AMDR: 10–35% of daily calories

  • Carbohydrates

    Preferred energy source for brain function and exercise performance.

    Calories: 4 kcal/g AMDR: 45–65% of daily calories

  • Fats

    Essential for hormone production, vitamin absorption, and long-term energy storage.

    Calories: 9 kcal/g AMDR: 20–35% of daily calories

Scientific basis: Dietary Guidelines for Americans 2020-2025 (Acceptable Macronutrient Distribution Range) and Pavlidou equation (2023)

Adjusting for fat loss, maintenance, or muscle gain

A macro calculator for muscle gain, fat loss, or maintenance starts from your TDEE, then applies goal-specific calorie adjustments and AMDR macro ratios — moderate changes tend to stick better than extreme cuts or surges.

  • Weight Loss

    Higher protein to preserve muscle during a moderate calorie deficit; moderate carbs; higher fat for satiety.

    Protein: 25% Carbs: 35% Fat: 40% Adjustment: ~15% calorie deficit from TDEE

  • Maintenance

    Balanced macronutrient distribution following AMDR guidelines for general health and performance.

    Protein: 20% Carbs: 50% Fat: 30% Adjustment: TDEE unchanged

  • Muscle Gain

    Higher carbs for training performance and recovery; adequate protein for muscle protein synthesis.

    Protein: 25% Carbs: 50% Fat: 25% Adjustment: ~10% calorie surplus from TDEE

  • Worked example: goal-specific macro grams

    • Weight Loss: 2,000 kcal: Protein 125g · Carbs 175g · Fat 89g
    • Maintenance: 2,200 kcal: Protein 110g · Carbs 275g · Fat 73g
    • Muscle Gain: 2,500 kcal: Protein 156g · Carbs 313g · Fat 69g
How it's calculated, sources and more

On this page vs in the app

The on-page macro calculator uses Pavlidou RMR with WHO/FAO physical-activity level (PAL) multipliers, then applies AMDR-based macro ratios for your goal. In the app, Carthalis adds the energy cost of the activities you log (MET values from the Adult Compendium of Physical Activities).

Methodology sources: Pavlidou et al. 2023 (RMR equation); FAO/WHO/UNU 2004 (PAL activity multipliers); Dietary Guidelines for Americans (AMDR). Pavlidou et al. 2023; FAO/WHO/UNU 2004; Dietary Guidelines AMDR. Compare with our TDEE calculator.

Macro estimates are general guidance — consult a clinician for medically supervised diets.

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Common questions

A macro calculator splits your daily calories into grams of protein, carbohydrates and fat. The free calculator on this page estimates your energy needs with the Pavlidou resting-metabolism equation and WHO/FAO activity levels, then splits them within the Acceptable Macronutrient Distribution Ranges (protein 10–35%, carbohydrate 45–65%, fat 20–35%) for fat loss, maintenance or muscle gain. A planning estimate, not a medical prescription.

Yes. Try the calculator on this page to estimate your protein, carb, and fat split using Pavlidou RMR, PAL multipliers, and AMDR-based ratios. Save your results with a free account; in the app, your estimate updates with the activities you log.

Acceptable Macronutrient Distribution Range guidelines suggest protein 10–35%, carbohydrates 45–65%, and fats 20–35% of daily calories. For weight loss, higher protein (about 25%) helps preserve muscle. For muscle gain, higher carbs (about 50%) support training performance. The on-page calculator applies goal-specific splits within AMDR — educational guidance, not individualized medical advice.

The RDA minimum is 0.8 g protein per kg body weight. Goal-based planning often uses higher shares: about 25% of calories for weight loss or muscle gain (muscle preservation and synthesis), and about 20% for maintenance. Your gram target depends on total calories — use the calculator on this page for an estimate, then save with a free account for ongoing tracking.

Yes. Macro grams are calculated from your total daily energy expenditure (TDEE). If calorie needs are misestimated, macro targets will be off. The on-page calculator uses Pavlidou RMR with PAL multipliers; in the app, your estimate uses the workouts you log, so targets follow your real activity.

Recalculate every 4–6 weeks, or when your weight, activity level, or goal changes meaningfully. Energy needs and macro grams shift as body mass and training volume change — adjust targets to stay aligned.

AMDR (Acceptable Macronutrient Distribution Range) is the evidence-based band for each macronutrient as a share of total calories, published in the Dietary Guidelines for Americans. It helps keep protein, carb, and fat intake within ranges associated with general health — a planning framework, not a clinical prescription.

No. Macro estimates on Carthalis are wellness education for nutrition planning — not medical diagnosis, treatment, or prescription. Discuss significant diet changes with a qualified clinician, especially with health conditions or medications.

Save your macros and plan meals

Create a free account to save your estimate. In the app it updates with the activities you log, alongside meal suggestions and meal logging against your targets.

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