{
  "entity_type": "unit_conversion_page",
  "id": "grains-to-grams",
  "name": "Grains to Grams",
  "title": "Grains to Grams Converter (grain to g)",
  "description": "Convert grains to grams: 1 grain = 0.0647989 g. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.",
  "quantity": "mass",
  "quantity_name": "Mass",
  "base_unit": "kg",
  "from_unit": {
    "symbol": "grain",
    "display": "grain",
    "name": "grains",
    "singular": "grain"
  },
  "to_unit": {
    "symbol": "g",
    "display": "g",
    "name": "grams",
    "singular": "gram"
  },
  "linear": true,
  "factor": 0.06479891,
  "inverse_factor": 15.43235835,
  "formula": "grams = grains × 0.06479891",
  "reverse_formula": "grains = grams × 15.43235835",
  "unit_relation": "1 grain = 0.0647989 g",
  "examples": [
    {
      "value": 5,
      "result": 0.323995,
      "text": "5 grain = 0.323995 g"
    },
    {
      "value": 12.5,
      "result": 0.809986,
      "text": "12.5 grain = 0.809986 g"
    },
    {
      "value": 100,
      "result": 6.47989,
      "text": "100 grain = 6.47989 g"
    }
  ],
  "table": [
    {
      "grain": 1,
      "g": 0.0647989
    },
    {
      "grain": 2,
      "g": 0.129598
    },
    {
      "grain": 3,
      "g": 0.194397
    },
    {
      "grain": 4,
      "g": 0.259196
    },
    {
      "grain": 5,
      "g": 0.323995
    },
    {
      "grain": 6,
      "g": 0.388793
    },
    {
      "grain": 7,
      "g": 0.453592
    },
    {
      "grain": 8,
      "g": 0.518391
    },
    {
      "grain": 9,
      "g": 0.58319
    },
    {
      "grain": 10,
      "g": 0.647989
    },
    {
      "grain": 15,
      "g": 0.971984
    },
    {
      "grain": 20,
      "g": 1.29598
    },
    {
      "grain": 25,
      "g": 1.61997
    },
    {
      "grain": 30,
      "g": 1.94397
    },
    {
      "grain": 40,
      "g": 2.59196
    },
    {
      "grain": 50,
      "g": 3.23995
    },
    {
      "grain": 75,
      "g": 4.85992
    },
    {
      "grain": 100,
      "g": 6.47989
    },
    {
      "grain": 200,
      "g": 12.9598
    },
    {
      "grain": 250,
      "g": 16.1997
    },
    {
      "grain": 500,
      "g": 32.3995
    },
    {
      "grain": 1000,
      "g": 64.7989
    }
  ],
  "faq": [
    {
      "q": "How many grams are in one grain?",
      "a": "1 grain = 0.0647989 g. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures."
    },
    {
      "q": "What is the formula to convert grains to grams?",
      "a": "Multiply the value in grains by 0.06479891: grams = grains × 0.06479891. For example, 5 grain = 0.323995 g."
    },
    {
      "q": "How do I convert grams back to grains?",
      "a": "Multiply by the inverse factor 15.43235835 (grains = grams × 15.43235835), or use the grams-to-grains page."
    }
  ],
  "sources": [
    {
      "name": "NIST Special Publication 811 – Guide for the Use of the International System of Units (SI), Appendix B conversion factors",
      "url": "https://www.nist.gov/pml/special-publication-811",
      "type": "standard",
      "retrieved_at": "2026-09-24"
    },
    {
      "name": "BIPM – The International System of Units (SI Brochure, 9th edition)",
      "url": "https://www.bipm.org/en/publications/si-brochure",
      "type": "standard",
      "retrieved_at": "2026-09-24"
    },
    {
      "name": "Wikipedia – Conversion of units",
      "url": "https://en.wikipedia.org/wiki/Conversion_of_units",
      "type": "reference",
      "retrieved_at": "2026-09-24"
    }
  ],
  "freshness": {
    "type": "static",
    "max_age_seconds": null,
    "note": "Fixed conversion factors (NIST/BIPM definitions); results never go stale."
  },
  "api": {
    "convert": "https://tttkmbb.com/api/v1/convert?value=5&from_unit=grain&to_unit=g",
    "calculator": "https://tttkmbb.com/api/v1/calculate/mass?value=5&from_unit=grain&to_unit=g",
    "mcp_tool": "convert_units",
    "mcp_arguments": {
      "value": 5,
      "from_unit": "grain",
      "to_unit": "g"
    }
  },
  "links": {
    "html": "https://tttkmbb.com/conversion/grains-to-grams",
    "markdown": "https://tttkmbb.com/conversion/grains-to-grams.md",
    "json": "https://tttkmbb.com/conversion/grains-to-grams.json",
    "reverse": "https://tttkmbb.com/conversion/grams-to-grains",
    "quantity_converter": "https://tttkmbb.com/conversion/mass",
    "units": "https://tttkmbb.com/api/v1/units?quantity=mass"
  },
  "timestamp": "2026-09-24"
}