MAP Calculator (Mean Arterial Pressure)

Mean Arterial Pressure (MAP) is the average arterial blood pressure throughout one complete cardiac cycle, including both systole (heart contraction) and diastole (heart relaxation). Because the heart spends more time in diastole, MAP is not simply the midpoint between systolic and diastolic — it weights diastole more heavily. MAP is considered the best indicator of perfusion pressure to vital organs.

The standard clinical formula for MAP is: MAP = Diastolic BP + (1/3 × Pulse Pressure), where Pulse Pressure = Systolic BP − Diastolic BP. This simplifies to MAP = (Systolic BP + 2 × Diastolic BP) / 3. This formula reflects that diastole occupies approximately two-thirds of the cardiac cycle.

A normal MAP is generally considered to be between 70 and 100 mmHg. A MAP of at least 60 mmHg is typically required to perfuse the coronary arteries, brain, and kidneys adequately. Values consistently above 100 mmHg may indicate hypertension, while values below 60 mmHg can signal inadequate organ perfusion.

MAP is used extensively in critical care and emergency medicine because it provides a more accurate measure of tissue and organ perfusion than systolic blood pressure alone. It is used to guide treatment targets in septic shock, traumatic brain injury, and post-cardiac arrest care. Many vasopressor protocols target a MAP of ≥65 mmHg.

A MAP below 60 mmHg is considered critically low and suggests that vital organs — including the brain, heart, and kidneys — may not be receiving adequate blood flow. This can result in organ ischemia or failure if not corrected promptly. Immediate medical evaluation and intervention are required.

Not exactly. While MAP represents a time-averaged arterial pressure, it is not a simple arithmetic mean of systolic and diastolic values. Because diastole lasts roughly twice as long as systole in a resting heart, MAP is calculated as a weighted average giving two-thirds weight to diastolic pressure and one-third to systolic pressure.

Pulse pressure is the difference between systolic and diastolic blood pressure (Systolic − Diastolic). A normal pulse pressure is typically 40 mmHg. It is directly used in the MAP formula and can independently signal cardiovascular risk — a widened pulse pressure (>60 mmHg) may indicate aortic stiffness or other cardiac conditions.

This calculator is intended for educational and informational purposes only. While the formula used matches standard clinical guidelines, any medical decisions — including treatment of abnormal MAP values — should always be made by a qualified healthcare professional with full clinical context.