{
  "id": "protein-for-muscle-gain",
  "version": "7343b412ef8c",
  "status": "published",
  "name": "Protein for Muscle Gain Calculator",
  "question": "How much protein for muscle gain?",
  "summary": "Estimates grams of protein a day for building muscle with resistance training, from body weight and a sourced range of 1.6 to 2.2 grams per kilogram.",
  "category": "health",
  "subcategory": "nutrition",
  "url": "https://www.acalculator.org/health/protein-for-muscle-gain-calculator",
  "markdown": "https://www.acalculator.org/health/protein-for-muscle-gain-calculator.md",
  "kind": "function",
  "method": "Protein a day (g) = body weight (kg) × 1.9, the middle of a range of 1.6 to 2.2 g per kg.",
  "assumptions": [
    "The range is 1.6 to 2.2 g per kg of body weight a day (0.73 to 1.00 g per lb), for adults doing resistance training.",
    "Weight is total body weight. For people with a lot of body fat, a dietitian may use a lower reference weight.",
    "Protein gives 4 calories per gram.",
    "This is an estimate for planning, not medical advice."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "weight": {
        "title": "Weight",
        "description": "Your body weight.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "mass",
        "minimum": 20,
        "maximum": 700
      }
    }
  },
  "outputs": {
    "protein": {
      "label": "Protein a day",
      "description": "Grams of protein a day: body weight × 1.9 g/kg, the middle of the range.",
      "format": "quantity",
      "unit": "g"
    },
    "low": {
      "label": "Range from",
      "description": "The low end of the range: body weight × 1.6 g/kg.",
      "format": "quantity",
      "unit": "g"
    },
    "high": {
      "label": "Range up to",
      "description": "The high end of the range: body weight × 2.2 g/kg.",
      "format": "quantity",
      "unit": "g"
    },
    "calories": {
      "label": "Calories from this protein",
      "description": "Calories a day from the protein: grams × 4.",
      "format": "number"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "weight": 81.6466266
    },
    "outputs": {
      "protein": 0.15512859054,
      "low": 0.13063460256,
      "high": 0.17962257852,
      "calories": 620.51436216
    },
    "text": "For muscle gain, aim for about 155 g of protein a day, in a range of 131 g to 180 g."
  },
  "examples": [
    {
      "given": {
        "weight": 81.6466266
      },
      "expect": {
        "protein": 0.15512859054,
        "low": 0.13063460256,
        "high": 0.17962257852,
        "calories": 620.51436216
      },
      "source": "hand calculation in content.mdx; Morton RW, Murphy KT, McKellar SR, et al. Br J Sports Med 2018;52(6):376-384 (gains in fat-free mass plateau at 1.62 g/kg a day, 95% CI 1.03 to 2.20), https://pmc.ncbi.nlm.nih.gov/articles/PMC5867436/ (retrieved 2026-11-01)"
    },
    {
      "given": {
        "weight": 70
      },
      "expect": {
        "protein": 0.133,
        "low": 0.112,
        "high": 0.154,
        "calories": 532
      },
      "source": "hand calculation in content.mdx; Morton RW, Murphy KT, McKellar SR, et al. Br J Sports Med 2018;52(6):376-384 (gains in fat-free mass plateau at 1.62 g/kg a day, 95% CI 1.03 to 2.20), https://pmc.ncbi.nlm.nih.gov/articles/PMC5867436/ (retrieved 2026-11-01)"
    },
    {
      "given": {
        "weight": 90.718474
      },
      "expect": {
        "protein": 0.1723651006,
        "low": 0.1451495584,
        "high": 0.1995806428,
        "calories": 689.4604024
      },
      "source": "the protein calculator's muscle goal at 200 lb; Morton RW, Murphy KT, McKellar SR, et al. Br J Sports Med 2018;52(6):376-384 (gains in fat-free mass plateau at 1.62 g/kg a day, 95% CI 1.03 to 2.20), https://pmc.ncbi.nlm.nih.gov/articles/PMC5867436/ (retrieved 2026-11-01)"
    }
  ],
  "sources": [
    "Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376-384 (break point 1.62 g/kg a day, 95% CI 1.03 to 2.20, p = 0.079). Retrieved 2026-11-01. https://pmc.ncbi.nlm.nih.gov/articles/PMC5867436/",
    "U.S. Code of Federal Regulations, 21 CFR 101.9(c)(1)(i)(B): general factors of 4 calories per gram of protein (Cornell LII copy). Retrieved 2026-11-01. https://www.law.cornell.edu/cfr/text/21/101.9",
    "NIST Guide to the SI (SP 811), Appendix B.8: the inch is exactly 0.0254 m; the avoirdupois pound is 0.4535924 kg to seven figures. Retrieved 2026-11-01. https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8"
  ],
  "related": [
    "protein",
    "macro",
    "calorie",
    "tdee"
  ],
  "changelog": []
}