{
  "id": "mean-arterial-pressure",
  "version": "079ef162ca6e",
  "status": "published",
  "name": "Mean Arterial Pressure Calculator",
  "question": "What is my mean arterial pressure?",
  "summary": "Estimates mean arterial pressure (MAP) from systolic and diastolic blood pressure as the diastolic pressure plus one third of the pulse pressure, or solves for any of the four from two.",
  "category": "health",
  "subcategory": "clinical",
  "url": "https://www.acalculator.org/health/mean-arterial-pressure-calculator",
  "markdown": "https://www.acalculator.org/health/mean-arterial-pressure-calculator.md",
  "kind": "formulas",
  "method": "MAP = DBP + (SBP − DBP) ÷ 3; pulse pressure = SBP − DBP.",
  "assumptions": [
    "The formula weights the diastolic pressure two thirds and the systolic one third, because at a resting heart rate diastole lasts about two thirds of each heartbeat.",
    "At fast heart rates systole takes a larger share of each beat, and the formula underestimates the true mean pressure (Razminia 2004).",
    "This is an estimate from a cuff reading, for information only; it is not a measured arterial pressure and not medical advice."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "sys": {
        "title": "Systolic (top number)",
        "description": "The systolic blood pressure.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "pressure",
        "minimum": 6666.119370750001,
        "maximum": 39996.7162245
      },
      "dia": {
        "title": "Diastolic (bottom number)",
        "description": "The diastolic blood pressure.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "pressure",
        "minimum": 2666.4477483,
        "maximum": 26664.477483000002
      },
      "map": {
        "title": "Mean arterial pressure",
        "description": "The mean arterial pressure (MAP).",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "pressure",
        "minimum": 2666.4477483,
        "maximum": 33330.59685375
      },
      "pp": {
        "title": "Pulse pressure",
        "description": "Systolic minus diastolic pressure.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "pressure",
        "exclusiveMinimum": 0,
        "maximum": 33330.59685375
      }
    }
  },
  "solve": {
    "fillAny": 2,
    "variables": [
      "sys",
      "dia",
      "map",
      "pp"
    ],
    "inputsOnly": []
  },
  "outputs": {
    "sys": {
      "label": "Systolic (top number)",
      "description": "The systolic blood pressure.",
      "format": "quantity"
    },
    "dia": {
      "label": "Diastolic (bottom number)",
      "description": "The diastolic blood pressure.",
      "format": "quantity"
    },
    "map": {
      "label": "Mean arterial pressure",
      "description": "MAP = diastolic + (systolic − diastolic) ÷ 3, to one decimal place.",
      "format": "quantity",
      "unit": "mmHg"
    },
    "pp": {
      "label": "Pulse pressure",
      "description": "Systolic minus diastolic pressure.",
      "format": "quantity",
      "unit": "mmHg"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "sys": 15998.6864898,
      "dia": 10665.7909932
    },
    "outputs": {
      "map": 12443.422825395557,
      "pp": 5332.8954966
    },
    "text": "A blood pressure of 120 mmHg/80 mmHg gives a mean arterial pressure of 93.3 mmHg."
  },
  "examples": [
    {
      "given": {
        "sys": 15998.6864898,
        "dia": 10665.7909932
      },
      "expect": {
        "map": 12443.4228254,
        "pp": 5332.8954966
      },
      "source": "MAP = DBP + (SBP − DBP) ÷ 3 (Razminia 2004; Meaney 2000): 80 + 40 ÷ 3 = 93.3 mmHg; hand calculation in content.mdx"
    },
    {
      "given": {
        "sys": 18665.1342381,
        "dia": 11999.01486735
      },
      "expect": {
        "map": 14221.0546576
      },
      "source": "MAP = DBP + (SBP − DBP) ÷ 3: 90 + 50 ÷ 3 = 106.7 mmHg; hand calculation in content.mdx"
    },
    {
      "given": {
        "map": 8665.955181975001,
        "dia": 6666.119370750001
      },
      "expect": {
        "sys": 12665.626804425003
      },
      "source": "SBP = 3 × MAP − 2 × DBP = 195 − 100 = 95 mmHg; hand calculation in content.mdx"
    },
    {
      "given": {
        "map": 13332.238741500001,
        "pp": 5999.507433675
      },
      "expect": {
        "dia": 11332.402930275,
        "sys": 17331.910363950003
      },
      "source": "DBP = MAP − PP ÷ 3 = 100 − 15 = 85 mmHg; SBP = 85 + 45 = 130 mmHg; hand calculation in content.mdx"
    }
  ],
  "sources": [
    "Razminia M, Trivedi A, Molnar J, et al. Validation of a new formula for mean arterial pressure calculation: the new formula is superior to the standard formula. Catheter Cardiovasc Interv. 2004;63(4):419-425 (the standard formula weights systolic 1/3 and diastolic 2/3). https://doi.org/10.1002/ccd.20217",
    "Meaney E, Alva F, Moguel R, Meaney A, Alva J, Webel R. Formula and nomogram for the sphygmomanometric calculation of the mean arterial pressure. Heart. 2000;84(1):64 (Figure 1 compares the standard multiplier of the pulse pressure, 0.333, with 0.412, against an electronically measured MAP). https://doi.org/10.1136/heart.84.1.64",
    "National Institute of Standards and Technology. Guide for the Use of the International System of Units (SI), NIST Special Publication 811, Appendix B (millimeter of mercury, conventional = 133.3224 Pa). https://www.nist.gov/pml/special-publication-811"
  ],
  "related": [
    "blood-pressure",
    "qtc",
    "gfr"
  ],
  "changelog": [
    {
      "date": "2026-09-30",
      "note": "Published after this site's editorial review against the cited sources (no clinician review); the page notices say so."
    }
  ]
}