🥩 Protein Intake Calculator – Evidence-Based Daily Targets
Protein is the most important macronutrient for body composition, muscle repair, satiety, and long-term health. Yet the popular advice to "eat more protein" rarely answers the critical question: how much protein do you actually need per day? This calculator provides a personalised, evidence-based answer using your body weight, activity level, and nutrition goal.
Why Protein Requirements Vary
The official Recommended Daily Allowance (RDA) of 0.8 g per kg of body weight was established as a minimum to prevent deficiency — not as an optimal target. Research consistently shows that physically active individuals, athletes, older adults, and those in a calorie deficit require substantially more protein to support muscle protein synthesis and lean mass retention.
Key factors that influence your protein needs include:
- Training type: Resistance training drives higher muscle protein turnover, requiring 1.6–2.2 g/kg/day for hypertrophy. Endurance athletes need 1.2–1.6 g/kg to support recovery and oxidative fuel.
- Calorie balance: During a calorie deficit, protein must rise (1.8–2.4 g/kg) to spare muscle tissue from being used as fuel.
- Age: Ageing reduces anabolic signalling (anabolic resistance), so adults over 65 typically need ≥1.2 g/kg/day to maintain muscle mass and counteract sarcopenia.
- Body composition: High body-fat individuals get more accurate targets by calculating protein relative to lean body mass rather than total weight.
How Protein Intake Is Calculated
The core formula is simple:
Daily Protein (g) = Base Weight (kg) × Protein Factor (g/kg)The protein factor is selected from evidence-based ranges adjusted for your goal and activity level. When body fat percentage or lean body mass is provided, the calculator substitutes lean mass for total weight, giving a more precise target:
Lean Body Mass (kg) = Body Weight × (1 − Body Fat % / 100)Supporting metrics are then derived:
Protein Calories = Daily Protein × 4 kcal/g Protein per Meal = Daily Protein ÷ Meals per Day Macro Share (%) = (Protein Calories ÷ Calorie Target) × 100Protein Targets by Goal
| Goal | Range (g/kg/day) | Notes |
|---|---|---|
| General Health | 0.8–1.1 | RDA minimum plus moderate activity buffer |
| Endurance Training | 1.2–1.6 | Supports oxidative fuel and recovery |
| Muscle Gain | 1.6–2.2 | Optimises muscle protein synthesis |
| Fat Loss / Cutting | 1.8–2.4 | Preserves lean mass during deficit |
| Body Recomposition | 1.6–2.4 | Simultaneously builds and preserves muscle |
| Healthy Aging (65+) | 1.0–1.6 | Counters anabolic resistance in older adults |
Per-Meal Distribution Matters
Muscle protein synthesis (MPS) is maximised when protein is distributed across multiple meals rather than concentrated in one. Research suggests consuming 0.4 g/kg of body weight per meal — roughly 25–40 g per serving — produces a near-maximal MPS stimulus. The calculator divides your daily target evenly across your chosen meal count, letting you plan whether to reach your target across 3, 4, or 6 meals.
Lean Body Mass Mode
For individuals with a body fat percentage above approximately 25%, calculating protein needs from lean body mass (LBM) provides a more accurate target. Fat tissue requires almost no dietary protein — it's skeletal muscle, organs, and connective tissue that drive protein turnover. Enter your body fat % and the tool will estimate your LBM automatically, or enter your LBM directly if you have a DEXA or BodPod measurement.
Protein and Calories
Protein provides 4 kcal per gram. If you supply a daily calorie target, the calculator displays protein's share of your total energy budget. A macro share of 25–35% is common for body-composition goals, while fat-loss phases may push it to 35–40%. The macro calorie bar visualises how much of your calorie budget protein occupies, helping you plan fat and carbohydrate allocations in the remaining calories.
Practical Tips for Hitting Your Protein Target
🍗 Animal sources (chicken breast, Greek yogurt, eggs, cottage cheese, fish) typically deliver 20–30 g per 100 g and contain all essential amino acids.
🌱 Plant sources (lentils, tofu, tempeh, edamame, quinoa) can meet targets when varied; consider combining sources to get a full amino acid profile.
🥛 Whey or casein protein supplements are convenient options when whole-food protein is hard to reach — especially post-workout.
📅 Consistency matters more than timing. Hitting your daily target across multiple meals is more important than the precise post-workout window.
Limitations and Disclaimers
All recommendations are based on population-level research and represent sensible evidence-based ranges rather than individually prescribed amounts. Certain medical conditions (kidney disease, liver impairment, metabolic disorders) may require different protein intake — consult a registered dietitian or physician for clinical guidance. Pregnancy and lactation also increase protein requirements beyond the standard ranges shown here.