Nutrition
Protein Intake Calculator
Get daily protein targets based on training level and goal.
Result
Daily protein range
Your target within the evidence-based range.
1.6–2 g per kg of body weight at 75 kg. About 34 g a meal across 4 meals; around 2.5 g of leucine a meal (roughly 25–30 g of whey, eggs or meat) is the usual target for muscle protein synthesis, and plant sources may need combining.
Published reference ranges
- 0.8 g/kg — RDA Minimum. Institute of Medicine, DRI 2005.
- 1.4–2 g/kg — ISSN Position Stand. Jäger et al. (2017), J Int Soc Sports Nutr.
- 2.3–3.1 g/kg of fat-free mass — Lean athletes in a calorie deficit. Helms et al. (2014), systematic review, Int J Sport Nutr Exerc Metab.
- 1.6–2.2 g/kg — Plateau for muscle gain with resistance training (to upper 95% CI). Morton et al. (2018), meta-analysis, Br J Sports Med.
Formula from Morton meta-analysis (2018) and ISSN protein position stand (2017), checked against the source on May 25, 2026.
What does the Protein Intake Calculator calculate, and which formula does it use?
The Protein Intake Calculator turns bodyweight, activity level, and goal into a daily protein target in grams, using g-per-kg bands from 1.2–1.6 (sedentary) up to 1.8–2.4 (athletes, +0.2 when cutting), benchmarked against published ranges including Morton 2018's 1.6–2.2 g/kg muscle-protein-synthesis ceiling and the ISSN's 1.4–2.0 g/kg. Plant-based eaters get a +10% adjustment.
Last updated .
How to use it
- Enter your body weight (kg, or lb with Units set to US), activity level and goal. The ranges are per kg of total body weight; if you carry a lot of body fat, entering your goal weight keeps the target realistic.
- Read the daily target (the middle of your range) with the low and high ends beside it, and the same range per kg or per lb of body weight. Hitting the low end consistently matters more than the exact number; the published reference ranges underneath show where your target sits.
- If your protein target feels hard to reach, track your current baseline for 3 days first. Most people are further from target than they think. Greek yogurt (17g/cup), cottage cheese (25g/cup), chicken breast (35g/4 oz) are high-density sources.
- Distribute protein across 3–4 meals (30–40g each) rather than concentrating it at dinner. This maximizes muscle protein synthesis better than identical total intake consumed in 1–2 large servings.
- Recalculate when body weight changes by 10+ lbs or when switching between cutting and bulking phases. The calculator adds 0.2 g/kg in a cut (and 0.1 g/kg in a bulk), because a calorie deficit raises the protein needed to hold on to muscle.
Questions people usually ask
Which formula is used here?
Uses grams-per-kilogram evidence ranges adjusted by activity level and goal.
Can I use metric or imperial units?
Yes. This tool supports both metric and imperial units and remembers your preference.
Is this medical advice?
No. This tool provides general fitness estimates and should not replace medical guidance.
Is this tool free and private to use?
Yes. AI Fit Hub tools are free, no-signup browser tools. Inputs stay in your browser unless you choose to share a URL.
Do these tools replace medical guidance?
No. These outputs are general fitness estimates — not medical advice.
Can I switch between metric and imperial units?
Yes. Every tool supports both systems and remembers your preference in localStorage.
The formula, worked through
- Formula Protein Intake Formula
protein_g = mass_kg × goal_factor. Goal factors: 0.8 sedentary (RDA), 1.6 trained baseline, 1.8 deficit / hypertrophy, 2.2 advanced cut or older lifter.
- Formula Creatine Loading Formula
Creatine loading formula: 0.3 g/kg/day for 5–7 days, split 4× daily. Maintenance: 0.03 g/kg/day or 3–5 g flat. Same saturation in ~7 vs ~28 days.
- Formula Macronutrient Ratio Formula
Macronutrient ratio formula: protein 1.6–2.2 g/kg, fat 0.6–1.0 g/kg (≥20% of calories), carbs = (total cal − protein·4 − fat·9) / 4.
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Background on the Protein Intake Calculator
- Guide Protein Timing: What the Research Actually Shows
Does the 'anabolic window' exist? Is protein timing important for muscle growth? We reviewed the meta-analyses. Here's what actually matters.
- Comparison Whey Isolate vs Concentrate: Which Protein to Buy
Whey isolate vs concentrate: concentrate is 70-80% protein and cheaper; isolate is 90%+ and low-lactose. Buy concentrate unless you need the purity.
- Examples Protein Intake Examples
Expert examples demystify protein intake. Learn optimal strategies for athletes, busy professionals, and older adults to boost recovery, satiety.
- Checklist Bulking Phase Checklist
Plan a structured bulking phase with this actionable checklist. Learn to optimize nutrition, training, and recovery for effective hypertrophy.
- Statistics Protein Intake Statistics: Daily Requirements & Effects
Evidence-based protein intake statistics: RDA baselines, optimal intakes for muscle gain, satiety effects, plant vs. animal protein research.
- Learn What Is Muscle Protein Synthesis? Simply Explained
Understand Muscle Protein Synthesis (MPS), the process for muscle growth and repair. Learn how exercise and diet stimulate MPS for optimal gains. AI Fit.
Articles
- 10 min read How to Build Muscle: The Evidence-Based Levers
Build muscle by ranking the five levers the research supports: volume, proximity to failure, load, frequency, and protein, each linked to its deep dive.
- 11 min read GLP-1 Muscle Loss: Keep Lean Mass with Lifting and Protein
GLP-1 weight loss costs lean mass: 25-39% of the total. How lifting 2-3x weekly and 1.2-1.6 g/kg protein hold muscle, and where the magnitude is debated.
- 13 min read Body Recomposition for Lifters: The Calorie Math
Body recomposition is real for specific populations under specific conditions. The four conditions, protein math scaled to LBM, 12-week example.
By goal
Use it from code
The same calculation as a JavaScript module you can import. It runs where you import it, with no request, key or rate limit.
import { compute } from "https://aifithub.io/engines/protein-intake-calculator.js";Input and output contract, TypeScript types and the guide for agents.