Protein Intake Calculator
Calculate your optimal daily protein intake in grams per day based on body weight, fitness goal, and activity level.
Calculate Daily Protein Intake (g/kg Bodyweight Method)
Enter your body weight, goal, and activity level to compute personalised protein targets.
Calculation Results
Calculated using verified sports nutrition standards: \text{Protein}_{\text{g/day}} = \text{Weight}_{kg} \times \text{g/kg ratio (goal + activity adjusted)}
\text{Protein energy: } 4\text{ kcal per gram}
Quick Summary
The Protein Intake Calculator evaluates daily protein requirements ($\text{Protein}_{\text{g}} = \text{Weight}_{\text{kg}} \times \text{g/kg ratio}$) personalised by fitness goal and training activity level, based on ISSN and ACSM sports nutrition position stands.
Formula Explanation
\text{Daily Protein} = \text{Weight}_{kg} \times \text{Ratio}_{g/kg}
\text{Ratios: Sedentary } 0.8-1.0 \to \text{Muscle Gain } 1.6-2.4\text{ g/kg}How It Works
The Protein Intake Calculator applies a base protein ratio (g protein per kg bodyweight per day) adjusted for both activity level (sedentary to very active) and primary fitness goal (maintenance, muscle gain, fat loss, or endurance). Ratios are sourced from the International Society of Sports Nutrition (ISSN) Position Stand on protein and exercise (Stokes et al. 2018).
Step-by-Step Worked Example
Practical Problem: A 75 kg male athlete training 5 days per week with the goal of gaining muscle mass. Calculate daily protein target.
- Step 1: Weight = 75 kg. Goal = Muscle Gain. Activity = Moderate (3-5 days/week).
- Step 2: Base ratio (moderate activity): 1.2–1.5 g/kg.
- Step 3: Muscle gain adjustment (+0.3–0.4 g/kg): Range = 1.5–1.9 g/kg.
- Step 4: Daily protein target: Min = 75 × 1.5 = 113 g/day. Max = 75 × 1.9 = 143 g/day.
- Step 5: Meal targets (3 meals/day): 38–48 g per meal. Protein energy = 452–572 kcal/day.
Real-World Calculation Examples
Scenario 1: 70 kg Endurance Runner
Goal: Endurance performance, 6 days/week
Result: 119–161 g/day (1.7–2.3 g/kg). Marathon runner protein needs.
Scenario 2: 85 kg Gym-Goer (Muscle Gain)
Goal: Muscle gain, 4 days/week
Result: 128–162 g/day (1.5–1.9 g/kg). Hypertrophy training protein target.
Scenario 3: 65 kg Female (Fat Loss)
Goal: Fat loss, 3 days/week
Result: 91–117 g/day (1.4–1.8 g/kg). Muscle-preserving diet protein.
Scenario 4: 90 kg Powerlifter (Strength)
Goal: Muscle gain, 2× daily training
Result: 171–225 g/day (1.9–2.5 g/kg). Elite strength athlete protein needs.
Key Benefits of Using This Calculator
Goal-Specific Protein Targets
Adjusts protein recommendations individually for maintenance, muscle gain, fat loss, and endurance performance goals.
ISSN & ACSM Standards
Based on International Society of Sports Nutrition (ISSN) and ACSM peer-reviewed protein position stands.
Per-Meal Protein Targets
Divides daily protein target into practical per-meal amounts for meal planning.
100% Free & Client-Side
Executes locally in your browser with zero latency or web server transmission.
Frequently Asked Questions (FAQ)
How much protein do I need per day?
The RDA minimum is 0.8 g/kg/day for sedentary adults. Athletes need 1.2–2.2 g/kg/day depending on goal and intensity.
How much protein do I need to build muscle?
Research supports 1.6–2.2 g/kg/day for maximizing muscle protein synthesis (MPS) during resistance training.
Can eating too much protein be harmful?
In healthy individuals with normal kidney function, intakes up to 3.0 g/kg/day have shown no adverse effects in the research literature.
How much protein can be absorbed per meal?
The anabolic ceiling for a single meal is approximately 20-40 g of protein — beyond this, excess amino acids are oxidized for energy.
What is the best protein source for athletes?
Complete proteins (containing all 9 essential amino acids) such as chicken, beef, eggs, dairy (whey), fish, and soy are optimal for MPS.
When should athletes consume protein for muscle growth?
Distributing protein evenly across 3-5 meals throughout the day maximizes total MPS. A 20-40 g protein dose within 2 hours post-exercise is beneficial.
How many calories does protein provide?
Protein provides 4 kcal per gram — the same as carbohydrates, but less than fat (9 kcal/g) and alcohol (7 kcal/g).
Do endurance runners need as much protein as bodybuilders?
Endurance runners need 1.4-1.7 g/kg/day (for muscle repair and mitochondrial adaptations), slightly less than bodybuilders needing 1.8-2.2 g/kg/day.
What is leucine threshold for muscle protein synthesis?
Approximately 2-3 g of leucine per meal is required to trigger maximal muscle protein synthesis — achieved by consuming 20-40 g of complete protein.
Does protein timing matter for performance?
Protein timing matters less than total daily protein intake. However, pre-sleep casein protein (30-40 g) improves overnight muscle protein synthesis.