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Mean Arterial Pressure (MAP) Calculator

The mean arterial pressure calculator computes MAP from systolic and diastolic blood pressure readings using the standard formula: MAP = (Systolic + 2 × Diastolic) ÷ 3. MAP is the average pressure in the arterial circulation throughout the cardiac cycle and is the key haemodynamic parameter used to assess adequate organ perfusion. A MAP of at least 60–65 mmHg is required to perfuse the brain, kidneys, and coronary arteries; in septic shock, a target MAP of ≥65 mmHg is a core resuscitation endpoint.

Mean Arterial Pressure

Formula

MAP = (Systolic + 2 × Diastolic) ÷ 3

Or equivalently:
MAP = Diastolic + 1/3 × (Systolic − Diastolic)
📖 Formula source: Hall JE. Guyton and Hall Textbook of Medical Physiology, 13th ed. Elsevier; 2016.

MAP Clinical Reference

MAP ValueInterpretation
< 60 mmHgCritical — inadequate organ perfusion (shock)
60–69 mmHgLow — monitor closely, intervene if symptomatic
70–100 mmHgNormal — adequate organ perfusion
101–110 mmHgElevated — hypertension, monitor
> 110 mmHgSeverely elevated — assess for hypertensive urgency/emergency

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Frequently Asked Questions

What is a normal mean arterial pressure?

Normal MAP is 70–100 mmHg. A MAP below 60 mmHg is considered critically low and indicates inadequate perfusion of vital organs. In clinical practice, a MAP of ≥65 mmHg is the standard target in patients with septic shock receiving vasopressors.

How is MAP different from average blood pressure?

MAP is not simply the average of systolic and diastolic — it is a weighted average that accounts for the fact that the heart spends approximately twice as long in diastole as in systole at normal heart rates. The formula MAP = (SBP + 2 × DBP) ÷ 3 reflects this weighting.

MAP is one component of haemodynamic assessment. Always interpret in the context of clinical signs, urine output, and the patient's baseline blood pressure.