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, log what you eat now for 3 days first, so you know how big the gap is. Dense sources per 100 g (USDA FoodData Central): plain Greek yogurt about 10 g, 2% cottage cheese about 10 g, roasted chicken breast about 31 g.
- Spread protein across 3–4 meals rather than loading it into dinner. The ISSN position stand suggests about 0.25 g per kg of body weight (20–40 g) per serving, evenly spaced every 3–4 hours (Jäger et al., 2017). The daily total still matters more than the timing.
- 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
How is my protein target calculated?
Your body weight times a grams-per-kilogram range for your activity level and goal; the target is the middle of that range, with 0.2 g/kg added in a cut and 0.1 g/kg in a bulk. The ranges are per kilogram of total body weight, so if you carry a lot of body fat, enter your goal weight instead.
How much protein do I need to build muscle?
In a meta-analysis of 49 trials, gains in fat-free mass levelled off at about 1.6 g per kg of body weight a day, with the upper confidence limit at 2.2 g/kg (Morton 2018). The ISSN recommends 1.4-2.0 g/kg a day for most people who exercise (Jäger 2017).
Do I need more protein when cutting?
Usually a little. A calorie deficit raises the protein needed to hold on to muscle; for lean, trained lifters dieting hard, Helms and colleagues suggest 2.3-3.1 g per kg of fat-free mass (Helms 2014). Most people get there by staying at the top of the normal range.
Does it matter how I spread protein across the day?
Somewhat. Daily total matters most, but 3-4 meals of roughly 0.25-0.40 g per kg each, including one within a couple of hours of training, is a practical pattern (Kerksick 2017).
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.
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Background on the Protein Intake Calculator
- Guide How to Calculate Macros for Bulking: A Complete Guide
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- Statistics Protein Intake Statistics: Daily Requirements & Effects
Protein intake statistics: the RDA, intakes that maximise muscle gain, satiety and plant vs animal protein, each figure with the study behind it.
- Learn What Is Muscle Protein Synthesis? Simply Explained
Muscle protein synthesis is how your body builds new muscle protein. What raises it, how lifting and protein intake combine, and why it drives growth.
- Statistics Supplement Industry Statistics: Use, Efficacy, & Safety
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Articles
- 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.
- 12 min read Protein for Muscle Gain: 1.6 g/kg (Morton 2018)
Morton 2018 placed the protein plateau at 1.6 g/kg with a 95% CI upper bound near 2.2 g/kg (49 studies, n=1,863). Cutting raises it to 2.3-3.1 g/kg lean.
- 7 min read How to Eat Enough Protein
Eating enough protein: the daily target by training goal, leucine threshold per meal, distribution across the day, and plant-based bioavailability adjustments.
By goal
Use it from an agent or code
Any agent can run this calculator by URL: put the inputs in the query string and get JSON back, with the inputs that used defaults and a line to cite (add format=md for markdown). MCP clients reach it through https://aifithub.io/mcp.
In code, import the same module; it runs where you import it, with no request or key.
import { compute } from "https://aifithub.io/engines/protein-intake-calculator.js";Input and output contract, TypeScript types and the guide for agents.