Nutrition & protein

Daily protein needs made simple.

Estimate your daily protein target from your body, activity, and goal — try the protein calculator on this page, then save your number with a free account.

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

Estimate your daily protein grams

Pavlidou RMR + PAL on this page for TDEE, then goal-based protein with the 0.8 g/kg RDA floor enforced. 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 track protein intake against this target, see meal suggestions, and adjust as your goal evolves.

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
  • Institute of Medicine 2002 — 0.8 g/kg/day protein RDA
  • Phillips, Chevalier & Leidy 2016 — context for higher intakes in muscle-gain settings (Appl Physiol Nutr Metab 41:565)

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What this number actually measures

Daily protein needs refer to how many grams of protein fit your total daily energy and fitness goal — an educational planning number from total daily energy expenditure, not a medical prescription. A protein calculator helps you estimate how much protein per day supports muscle repair, satiety, and recovery without guessing a one-size-fits-all rule.

  • Muscle building & repair

    Protein provides amino acids to build and repair muscle tissue after exercise and daily wear.

    Key benefit: Supports muscle protein synthesis

  • Satiety & weight management

    Protein is the most satiating macronutrient, helping you feel full longer and reducing overall calorie intake.

    Key benefit: Supports weight loss and maintenance

  • Metabolic boost

    Protein has the highest thermic effect of food — your body burns more calories digesting it than carbs or fat.

    Key benefit: Adds modest daily calorie burn

  • Immune function

    Protein helps produce antibodies and supports recovery — part of a balanced wellness picture.

    Key benefit: Supports everyday health and recovery

Recommended Dietary Allowance: The RDA minimum is 0.8 g/kg for adults — a deficiency floor, not necessarily the optimal target for active training or body-composition goals. Dietary Guidelines for Americans 2020-2025 and Pavlidou equation (2023).

Adjusting for fat loss, maintenance, or muscle gain

Goal shapes your protein share — fat loss and muscle gain often use about 25% of calories from protein; maintenance often uses about 20%. Gram targets depend on total calories — try the on-page estimate, then save with a free account.

  • Weight Loss

    Higher protein (about 25% of calories) to preserve muscle during a moderate calorie deficit and support satiety.

    Protein: 25% of calories Adjustment: ~15% calorie deficit from TDEE Minimum: 0.8 g/kg body weight (RDA minimum) Target range: 1.6–2.2 g/kg body weight (educational context)

  • Maintenance

    Balanced protein (about 20% of calories) to maintain muscle mass and support daily activities.

    Protein: 20% of calories Adjustment: TDEE unchanged Minimum: 0.8 g/kg body weight (RDA minimum) Target range: 1.0–1.4 g/kg body weight (educational context)

  • Muscle Gain

    Adequate protein (about 25% of calories) to support muscle protein synthesis while leaving room for training carbs.

    Protein: 25% of calories Adjustment: ~10% calorie surplus from TDEE Minimum: 0.8 g/kg body weight (RDA minimum) Target range: 1.6–2.2 g/kg body weight (educational context)

  • Worked example: goal-specific protein grams (70 kg reference)

    • Weight Loss: 70 kg person, 2,000 kcal: 125g protein
    • Maintenance: 70 kg person, 2,400 kcal: 120g protein
    • Muscle Gain: 70 kg person, 2,800 kcal: 175g protein
How it's calculated, sources and more

On this page vs in the app

The on-page protein calculator uses a three-step flow: estimate TDEE with Pavlidou RMR and WHO/FAO PAL multipliers, adjust calories for your goal, then apply a goal-based protein share while meeting the RDA minimum. In the app, Carthalis adds the energy cost of the activities you log (MET values from the Adult Compendium of Physical Activities).

Step 1: Estimate total daily energy using Pavlidou RMR and PAL multipliers.

Step 2: Adjust calories for your goal — about 15% deficit for fat loss, about 10% surplus for muscle gain, maintenance unchanged.

Step 3: Set protein as a share of calories while meeting the 0.8 g/kg RDA minimum.

Methodology sources: Pavlidou et al. 2023; FAO/WHO/UNU 2004; Dietary Guidelines for Americans. Compare with our calorie calculator.

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

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Common questions

A protein calculator estimates how many grams of protein to eat each day for your goal. The free calculator on this page estimates your energy needs (Pavlidou equation, WHO/FAO activity levels), then sets protein at about 25% of calories for weight loss or muscle gain and 20% for maintenance, never below the 0.8 g/kg RDA. A planning estimate, not a medical prescription.

Yes. Try the calculator on this page to estimate your daily protein grams using Pavlidou RMR, PAL multipliers, and goal-based protein shares. Save your results with a free account; in the app, your estimate updates with the activities you log.

The on-page calculator first estimates total daily energy using the Pavlidou RMR equation and WHO/FAO physical-activity level multipliers, adjusts calories for your goal (about 15% deficit for fat loss, about 10% surplus for muscle gain), then sets protein as a share of calories while meeting the 0.8 g/kg RDA minimum. In the app, your estimate uses the workouts you log.

The Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight for adults — the minimum to prevent deficiency, not necessarily the optimal amount for active training or specific body-composition goals. Goal-based planning often uses higher shares of total calories.

For fat loss, the calculator uses about 25% of calories from protein to help preserve lean mass and support satiety during a moderate calorie deficit. Gram targets depend on total calories — use the on-page estimate, then save with a free account for ongoing tracking.

For muscle gain, about 25% of calories from protein supports muscle protein synthesis while leaving room for carbohydrates that fuel training. Total grams rise with calorie surplus — estimate on this page, then save targets in the app.

You can run an estimate on this page without signing in. Create a free account to save your protein target, track changes over time, with meal suggestions and meal logging against your daily targets.

No. Protein 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 number 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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