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

Wellness education, not diagnosis · Not for emergencies

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).

Estimate your daily protein

Use the protein calculator on this page — a daily protein needs calculator for muscle gain, fat loss, or maintenance. Pavlidou RMR + PAL on this page; MET depth unlocks in the app.

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)

Sign up to use the more accurate MET-based estimation in the app, plus tools such as meal suggestions, meal planning, and meal logging / optimization against your daily targets.

Wellness education, not diagnosis.

Pavlidou RMR + PAL on this page vs MET-based 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. After signup, Carthalis adds activity-specific MET depth — honest tiering, not unverified superiority claims.

AspectOn this page (PAL + protein share)In the app (MET)
Resting metabolismPavlidou et al. 2023 (RMR equation)Same Pavlidou RMR base with profile refinements over time
Activity multiplierFAO/WHO/UNU 2004 (PAL activity multipliers)Activity-specific MET values when you log movement
Protein targetGoal-based protein share of calories + 0.8 g/kg RDA floorSame targets with meal logging and optimization against daily goals
Meal toolsEducational protein gram estimate onlyMeal suggestions, planning, and logging against targets

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.

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

Wellness education, not diagnosis

Wellness education, not diagnosis.

Not for emergencies — call your local emergency line.

Carthalis is not a medical device.

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

Read our full trust commitment on Trust & Safety.

Common questions

A daily protein calculator estimates grams of protein for your energy needs and fitness goal — educational planning numbers from total daily energy expenditure, not a medical prescription. Carthalis is a personal health companion for nutrition clarity: try the protein calculator on this page using the Pavlidou RMR equation with WHO/FAO physical-activity level multipliers, then apply goal-based protein shares (about 25% of calories for weight loss or muscle gain, 20% for maintenance) while meeting the 0.8 g/kg RDA minimum. Create a free account to save targets and unlock MET-based estimation plus meal suggestions, meal planning, and logging against daily goals. On-page results use simplified PAL factors; the app adds activity-specific MET depth when you log workouts or connect optional wearables. Carthalis provides wellness education, not medical diagnosis or treatment, and is not for emergencies — call your local emergency line for urgent care. Protein estimates are general guidance; consult a clinician for medically supervised diets. Carthalis is not a medical device. You control what you share.

Save your number and plan meals

Sign up to use the more accurate MET-based estimation in the app, plus tools such as meal suggestions, meal planning, and meal logging / optimization against your daily targets.