{
  "id": "blood-pressure",
  "version": "c6b707303d9f",
  "status": "published",
  "name": "Blood Pressure Calculator",
  "question": "What is my blood pressure category?",
  "summary": "Finds the adult blood pressure category (normal, elevated, stage 1 or stage 2 hypertension) from one to three readings, by the ACC/AHA guideline.",
  "category": "health",
  "subcategory": "body",
  "url": "https://www.acalculator.org/health/blood-pressure-calculator",
  "markdown": "https://www.acalculator.org/health/blood-pressure-calculator.md",
  "kind": "function",
  "method": "Average the readings and round half up to whole mmHg; systolic: under 120 normal, 120 to 129 elevated, 130 to 139 stage 1, 140 and over stage 2; diastolic: under 80 normal, 80 to 89 stage 1, 90 and over stage 2; the category is the higher of the two.",
  "assumptions": [
    "The categories are those of the 2017 ACC/AHA guideline for adults, which the 2025 AHA/ACC guideline kept.",
    "The guideline classifies the average of two or more readings taken on two or more occasions; one reading is a snapshot, not a diagnosis.",
    "This is not medical advice. Talk to a health care provider about your readings."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "sys": {
        "title": "Systolic (top number)",
        "description": "The systolic pressure of the reading, in mmHg.",
        "type": "integer",
        "minimum": 60,
        "maximum": 300
      },
      "dia": {
        "title": "Diastolic (bottom number)",
        "description": "The diastolic pressure of the reading, in mmHg.",
        "type": "integer",
        "minimum": 30,
        "maximum": 200
      },
      "sys2": {
        "title": "Second reading: systolic",
        "description": "The systolic pressure of a second reading, in mmHg.",
        "type": "integer",
        "minimum": 60,
        "maximum": 300
      },
      "dia2": {
        "title": "Second reading: diastolic",
        "description": "The diastolic pressure of a second reading, in mmHg.",
        "type": "integer",
        "minimum": 30,
        "maximum": 200
      },
      "sys3": {
        "title": "Third reading: systolic",
        "description": "The systolic pressure of a third reading, in mmHg.",
        "type": "integer",
        "minimum": 60,
        "maximum": 300
      },
      "dia3": {
        "title": "Third reading: diastolic",
        "description": "The diastolic pressure of a third reading, in mmHg.",
        "type": "integer",
        "minimum": 30,
        "maximum": 200
      }
    }
  },
  "outputs": {
    "category": {
      "label": "Blood pressure category",
      "description": "The higher of the systolic and diastolic categories: normal, elevated, stage 1 hypertension or stage 2 hypertension.",
      "format": "text"
    },
    "sysAvg": {
      "label": "Systolic",
      "description": "The systolic pressure, averaged over the readings and rounded half up to a whole mmHg.",
      "format": "integer"
    },
    "diaAvg": {
      "label": "Diastolic",
      "description": "The diastolic pressure, averaged over the readings and rounded half up to a whole mmHg.",
      "format": "integer"
    },
    "readings": {
      "label": "Readings averaged",
      "description": "How many readings the category is based on.",
      "format": "integer"
    },
    "severe": {
      "label": "Note",
      "description": "Shown when the average is above 180 systolic or 120 diastolic, the severe range in the guideline.",
      "format": "text"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "sys": 118,
      "dia": 76
    },
    "outputs": {
      "category": "Normal",
      "sysAvg": 118,
      "diaAvg": 76,
      "readings": 1
    },
    "text": "A blood pressure of 118/76 mmHg is Normal."
  },
  "examples": [
    {
      "given": {
        "sys": 118,
        "dia": 76
      },
      "expect": {
        "category": "Normal",
        "sysAvg": 118,
        "diaAvg": 76,
        "readings": 1
      },
      "source": "2017 ACC/AHA guideline, Table 6: normal is systolic under 120 and diastolic under 80"
    },
    {
      "given": {
        "sys": 124,
        "dia": 78
      },
      "expect": {
        "category": "Elevated"
      },
      "source": "2017 ACC/AHA guideline, Table 6: elevated is systolic 120 to 129 and diastolic under 80"
    },
    {
      "given": {
        "sys": 128,
        "dia": 84
      },
      "expect": {
        "category": "Stage 1 hypertension"
      },
      "source": "2017 ACC/AHA guideline, Table 6 and its note: a person in two categories is in the higher one"
    },
    {
      "given": {
        "sys": 132,
        "dia": 78,
        "sys2": 127,
        "dia2": 80,
        "sys3": 130,
        "dia3": 79
      },
      "expect": {
        "sysAvg": 130,
        "diaAvg": 79,
        "readings": 3,
        "category": "Stage 1 hypertension"
      },
      "source": "2017 ACC/AHA guideline: classify the average of the readings; hand calculation in content.mdx"
    },
    {
      "given": {
        "sys": 185,
        "dia": 95
      },
      "expect": {
        "category": "Stage 2 hypertension",
        "severe": "Above 180/120 mmHg, the severe range in the guideline. Measure again after a rest and talk to a health care provider."
      },
      "source": "2017 ACC/AHA guideline (stage 2 is 140/90 and over); 2025 AHA/ACC guideline (severe above 180/120)"
    }
  ],
  "sources": [
    "Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. Hypertension. 2018;71(6):e13-e115 (Table 6, categories of BP in adults). https://doi.org/10.1161/HYP.0000000000000065",
    "Jones DW, Ferdinand KC, Taler SJ, et al. 2025 AHA/ACC/AANP/AAPA/ABC/ACCP/ACPM/AGS/AMA/ASPC/NMA/PCNA/SGIM Guideline for the Prevention, Detection, Evaluation and Management of High Blood Pressure in Adults. Circulation. 2025;152(11):e114-e218. https://doi.org/10.1161/CIR.0000000000001356",
    "Giacona JM, Vongpatanasin W. The 2025 AHA/ACC Hypertension Guidelines: key updates, historical context, and clinical implications. Curr Cardiol Rep. 2026;28:90 (the 2025 guideline keeps the 2017 categories; severe hypertension is above 180 and/or 120 mmHg). https://doi.org/10.1007/s11886-026-02413-0"
  ],
  "related": [
    "heart-rate-zone",
    "prevent",
    "ascvd-risk"
  ],
  "changelog": []
}