Mean Arterial Pressure Calculator

About this calculator

Mean arterial pressure approximates the average pressure driving blood through the arterial system across a full cardiac cycle, using MAP = DBP + (SBP − DBP)/3, or equivalently diastolic pressure plus one-third of the pulse pressure. The one-third weighting reflects that, at a typical resting heart rate, roughly two-thirds of the cardiac cycle is spent in diastole and only one-third in systole, so MAP sits closer to diastolic than to systolic pressure.

Critical care physicians and anesthesiologists track MAP because it better predicts organ perfusion than either systolic or diastolic pressure alone; a MAP of at least 65 mmHg is a commonly cited threshold for adequate perfusion of the brain, kidneys and other vital organs in critically ill patients. Nurses and paramedics use this quick formula at the bedside when continuous arterial line monitoring isn't available.