Mean Arterial Pressure Calculator
Mean arterial pressure (MAP) is the average blood pressure in the arteries during one complete cardiac cycle. Unlike the simple average of systolic and diastolic readings, MAP accounts for the fact that the heart spends roughly twice as long in diastole (relaxation) as in systole (contraction). This makes MAP a more accurate measure of the perfusion pressure that drives blood to vital organs such as the brain, kidneys, and heart. Clinicians use MAP to assess circulatory adequacy in critical care settings, where maintaining a MAP of at least 65 mmHg is a key treatment target. Enter your systolic and diastolic blood pressure readings below to calculate your MAP and see how it compares to the normal range.
MAP formula
MAP = Diastolic + (1/3) x (Systolic - Diastolic)
Equivalently: MAP = (Systolic + 2 x Diastolic) / 3
For a reading of 120/80: MAP = 80 + (1/3) x (120 - 80) = 80 + 13.33 = 93.33 mmHg.
MAP reference ranges
- Below 60 mmHg: critically low - inadequate organ perfusion
- 60-70 mmHg: low normal - may require monitoring
- 70-100 mmHg: normal range
- Above 100 mmHg: elevated - consistent with hypertension
Mean arterial pressure: frequently asked questions
What is mean arterial pressure (MAP)?
MAP is the average arterial pressure throughout one cardiac cycle. It is weighted toward diastole because the heart spends more time in that phase (roughly two-thirds of the cycle). MAP provides a better estimate of perfusion pressure to organs than systolic alone.
What is a normal MAP value?
A normal MAP is generally considered to be between 70 and 100 mmHg. A MAP below 60 mmHg is considered dangerously low and may result in inadequate blood flow to vital organs including the brain and kidneys.
How is MAP calculated?
The standard clinical formula is: MAP = Diastolic + (1/3) x (Systolic - Diastolic). This accounts for the fact that diastole takes up about two-thirds of the cardiac cycle. An alternative approximation is (Systolic + 2 x Diastolic) / 3.
Why is MAP important in critical care?
In ICU settings, a MAP of at least 65 mmHg is often used as a target to ensure adequate perfusion of vital organs. During septic shock or hypotension, vasopressors are titrated to maintain MAP above this threshold.
Is MAP the same as average blood pressure?
MAP is not a simple arithmetic average of systolic and diastolic. Because the heart spends about twice as long in diastole as in systole, MAP is closer to diastolic pressure. It is the time-weighted average, reflecting perfusion pressure over the full cardiac cycle.
Official sources
- National Heart, Lung, and Blood Institute: High Blood Pressure.
- Society of Critical Care Medicine: Critical Care Guidelines.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.