{
  "id": "cholesterol-ratio",
  "version": "021a0f6565ef",
  "status": "published",
  "name": "Cholesterol Ratio Calculator",
  "question": "What is my cholesterol ratio?",
  "summary": "Divides total cholesterol by HDL cholesterol (the Castelli index) and compares the ratio with the published risk level for men and for women.",
  "category": "health",
  "subcategory": "clinical",
  "url": "https://www.acalculator.org/health/cholesterol-ratio-calculator",
  "markdown": "https://www.acalculator.org/health/cholesterol-ratio-calculator.md",
  "kind": "function",
  "method": "Ratio = total cholesterol ÷ HDL cholesterol (same units), to 1 decimal. Risk level (Millán 2009, Table 1, primary prevention): over 5.0 for men, over 4.5 for women.",
  "assumptions": [
    "Total and HDL cholesterol come from the same blood sample.",
    "The ratio is rounded once to 1 decimal, halves away from zero, and the shown value is compared with the risk level."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "sex": {
        "title": "Sex",
        "description": "The published risk levels differ for men and women.",
        "type": "string",
        "enum": [
          "male",
          "female"
        ]
      },
      "units": {
        "title": "Units",
        "description": "US units (mg/dL) or SI units (mmol/L).",
        "type": "string",
        "enum": [
          "us",
          "si"
        ]
      },
      "tc": {
        "title": "Total cholesterol (mg/dL)",
        "description": "Total cholesterol, 50 to 1,000 mg/dL.",
        "type": "number",
        "minimum": 50,
        "maximum": 1000
      },
      "tcSi": {
        "title": "Total cholesterol (mmol/L)",
        "description": "Total cholesterol, 1.3 to 25.9 mmol/L.",
        "type": "number",
        "minimum": 1.3,
        "maximum": 25.9
      },
      "hdl": {
        "title": "HDL cholesterol (mg/dL)",
        "description": "HDL (\"good\") cholesterol, 5 to 200 mg/dL.",
        "type": "number",
        "minimum": 5,
        "maximum": 200
      },
      "hdlSi": {
        "title": "HDL cholesterol (mmol/L)",
        "description": "HDL (\"good\") cholesterol, 0.13 to 5.17 mmol/L.",
        "type": "number",
        "minimum": 0.13,
        "maximum": 5.17
      }
    }
  },
  "outputs": {
    "ratio": {
      "label": "Total to HDL cholesterol ratio",
      "description": "Total cholesterol ÷ HDL cholesterol, to 1 decimal.",
      "format": "number"
    },
    "level": {
      "label": "Risk level",
      "description": "Whether the ratio is above the primary-prevention risk level for the chosen sex (Millán 2009).",
      "format": "text"
    },
    "nonHdl": {
      "label": "Non-HDL cholesterol (mg/dL)",
      "description": "Total cholesterol minus HDL cholesterol, in mg/dL, to a whole number.",
      "format": "number"
    },
    "nonHdlSi": {
      "label": "Non-HDL cholesterol (mmol/L)",
      "description": "Total cholesterol minus HDL cholesterol, in mmol/L, to 2 decimals.",
      "format": "number"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "sex": "male",
      "units": "us",
      "tc": 200,
      "tcSi": 5.2,
      "hdl": 50,
      "hdlSi": 1.3
    },
    "outputs": {
      "ratio": 4,
      "level": "5.0 or less, not above the risk level for men",
      "nonHdl": 150,
      "nonHdlSi": 3.88
    },
    "text": "The total to HDL cholesterol ratio is 4: 5.0 or less, not above the risk level for men."
  },
  "examples": [
    {
      "given": {
        "sex": "male",
        "units": "us",
        "tc": 200,
        "hdl": 50
      },
      "expect": {
        "ratio": 4,
        "level": "5.0 or less, not above the risk level for men",
        "nonHdl": 150,
        "nonHdlSi": 3.88
      },
      "source": "200 ÷ 50 = 4.0; Millán et al. 2009, Table 1, men over 5.0 (hand calculation in content.mdx)"
    },
    {
      "given": {
        "sex": "male",
        "units": "us",
        "tc": 220,
        "hdl": 40
      },
      "expect": {
        "ratio": 5.5,
        "level": "Above 5.0, the risk level for men",
        "nonHdl": 180
      },
      "source": "220 ÷ 40 = 5.5, over 5.0 (Millán et al. 2009, Table 1) (hand calculation in content.mdx)"
    },
    {
      "given": {
        "sex": "female",
        "units": "us",
        "tc": 190,
        "hdl": 42
      },
      "expect": {
        "ratio": 4.5,
        "level": "4.5 or less, not above the risk level for women"
      },
      "source": "190 ÷ 42 = 4.524, rounded to 4.5; women over 4.5 (Millán et al. 2009, Table 1) (hand calculation in content.mdx)"
    },
    {
      "given": {
        "sex": "female",
        "units": "us",
        "tc": 220,
        "hdl": 40
      },
      "expect": {
        "ratio": 5.5,
        "level": "Above 4.5, the risk level for women"
      },
      "source": "220 ÷ 40 = 5.5, over 4.5 (Millán et al. 2009, Table 1) (hand calculation)"
    },
    {
      "given": {
        "sex": "female",
        "units": "si",
        "tcSi": 5.2,
        "hdlSi": 1.3
      },
      "expect": {
        "ratio": 4,
        "nonHdlSi": 3.9,
        "nonHdl": 151
      },
      "source": "5.2 ÷ 1.3 = 4.0; non-HDL 3.9 mmol/L = 3.9 ÷ 0.02586 = 150.8 mg/dL (hand calculation in content.mdx)"
    }
  ],
  "sources": [
    "Millán J, Pintó X, Muñoz A, et al. Lipoprotein ratios: physiological significance and clinical usefulness in cardiovascular prevention. Vasc Health Risk Manag. 2009;5:757-765. https://doi.org/10.2147/vhrm.s6269 (open at https://pmc.ncbi.nlm.nih.gov/articles/PMC2747394/, retrieved 2026-10-05)",
    "Kinosian B, Glick H, Garland G. Cholesterol and coronary heart disease: predicting risks by levels and ratios. Ann Intern Med. 1994;121(9):641-647. https://doi.org/10.7326/0003-4819-121-9-199411010-00002 (retrieved 2026-10-05)"
  ],
  "related": [],
  "changelog": [
    {
      "date": "2026-10-05",
      "note": "Published after this site's editorial review against the cited sources (no clinician review); the page notices say so."
    }
  ]
}