Mean Arterial Pressure Calculator

What Is Mean Arterial Pressure (MAP)?

Mean arterial pressure (MAP) is the average arterial pressure during a single cardiac cycle. It represents the driving pressure for tissue perfusion and is a critical vital sign in emergency medicine, critical care, and anesthesia. MAP below 60 mmHg may fail to maintain adequate organ blood flow, while sustained elevation increases cardiovascular risk. Use the Cardiac Output Calculator to assess hemodynamic status and the INR Calculator when anticoagulation affects bleeding risk in hypotensive patients.

How MAP Is Calculated

The standard formula is MAP = (SBP + 2 × DBP) / 3, where SBP is systolic blood pressure and DBP is diastolic blood pressure, both in mmHg. Diastole lasts roughly twice as long as systole in normal sinus rhythm, so diastolic pressure is weighted twice. An alternative approximation, MAP ≈ DBP + 1/3 × (SBP − DBP), gives the same result. Pulse pressure (SBP − DBP) reflects stroke volume and arterial stiffness.

MAP, Perfusion, and Clinical Targets

Adequate MAP is essential for cerebral, renal, and coronary perfusion. Guidelines often target MAP ≥ 65 mmHg in septic shock and MAP ≥ 60 mmHg as a minimum perfusion threshold. In hypertensive emergencies, MAP above 160 mmHg may increase cerebral blood flow and intracranial pressure. Wide pulse pressure suggests increased stroke volume or reduced arterial compliance, while narrow pulse pressure may indicate hypovolemia or reduced cardiac output.