What is the MAP formula?

The standard clinical formula is MAP = (2 x DBP + SBP) / 3. Because the cardiac cycle spends roughly two-thirds of its time in diastole (relaxation) and one-third in systole (contraction), diastolic pressure is weighted twice as heavily as systolic pressure in the time-averaged calculation. An equivalent form is MAP = DBP + (1/3) x (SBP - DBP).

What is a normal MAP?

For a healthy adult at rest, 70-100 mmHg is the widely cited normal range. Most clinical guidelines use 65 mmHg as the minimum adequate perfusion target in sepsis management, while values above 100-110 mmHg indicate hypertension territory.

Why does MAP matter more than systolic or diastolic alone?

MAP is the time-averaged driving pressure that perfuses organs throughout the entire cardiac cycle. Systolic pressure lasts only about one-third of each cycle, so a single systolic reading overstates the sustained force available to push blood to the brain, kidneys, and other organs. MAP captures both phases and is therefore the pressure used in cerebral perfusion pressure calculations and in sepsis resuscitation targets.

What is a dangerous MAP?

Below 60 mmHg there is significant risk of inadequate organ perfusion, especially to the brain and kidneys. Below 50 mmHg is considered a medical emergency. Persistently elevated MAP above 110 mmHg corresponds to significant hypertension and warrants medical review.

What is pulse pressure, and why is it shown?

Pulse pressure is SBP minus DBP and represents the stroke volume-dependent pressure wave felt at the periphery. A normal resting value is roughly 40 mmHg. Widened pulse pressure (above 60 mmHg) can suggest aortic regurgitation or increased arterial stiffness; narrowed pulse pressure (below 25 mmHg) may indicate cardiac tamponade, severe aortic stenosis, or significant hypovolaemia.

Is this calculator suitable for clinical use?

No. This tool is for educational and reference purposes only. It performs the standard arithmetic correctly, but it cannot account for measurement technique, equipment calibration, patient position, recent activity, or any clinical context. Always use properly validated equipment and consult a qualified healthcare professional for clinical decisions.

Mean Arterial Pressure (MAP) Calculator

Mean Arterial Pressure (MAP) is the single number that most accurately captures the sustained driving force behind organ perfusion throughout the entire cardiac cycle. While a blood pressure reading shows two numbers — systolic over diastolic — MAP combines them into one time-weighted average that reflects how hard the heart is actually pushing blood to the brain, kidneys, liver, and every other vital organ during both the contraction and relaxation phases of the heartbeat.

This calculator uses the standard clinical formula and instantly classifies your result against the accepted reference ranges used in intensive care, emergency medicine, and general practice.

How it works

The heart spends approximately one-third of each cardiac cycle in systole (contraction) and two-thirds in diastole (relaxation). MAP is therefore a weighted average that gives diastolic pressure twice the contribution of systolic pressure:

MAP = (2 x DBP + SBP) / 3

An algebraically identical form, often easier to reason about, is:

MAP = DBP + (1/3) x (SBP - DBP)

Here the term (SBP - DBP) is the pulse pressure — the pressure wave generated by each stroke — and the formula simply adds one-third of that wave to the diastolic baseline.

The calculator also reports pulse pressure (SBP minus DBP) directly, because abnormally wide or narrow pulse pressure carries its own clinical significance separate from MAP.

Reference ranges (adults at rest)

MAP (mmHg)	Interpretation
Below 50	Critical — organ perfusion severely compromised
50–59	Low — significant perfusion risk
60–69	Low-normal — below optimal threshold
70–100	Normal range
101–110	Elevated — hypertension territory
Above 110	High — significant hypertension

In sepsis protocols (e.g. Surviving Sepsis Campaign), 65 mmHg is the minimum MAP resuscitation target. Cerebral perfusion pressure (CPP) is calculated as MAP minus intracranial pressure (ICP), so maintaining adequate MAP is critical in neurotrauma care.

Worked example

A patient presents with a blood pressure of 130 / 85 mmHg:

SBP = 130, DBP = 85
MAP = (2 x 85 + 130) / 3 = (170 + 130) / 3 = 300 / 3 = 100 mmHg
Pulse pressure = 130 - 85 = 45 mmHg (normal)

At exactly 100 mmHg this sits at the upper boundary of the normal range — mildly elevated and worth monitoring. Now consider a hypotensive patient at 90 / 50 mmHg:

MAP = (2 x 50 + 90) / 3 = (100 + 90) / 3 = 190 / 3 = 63.3 mmHg
Pulse pressure = 90 - 50 = 40 mmHg (normal)

At 63 mmHg the MAP is technically above the 60 mmHg threshold but below the conventional 65 mmHg sepsis target — a clinical prompt to intervene before perfusion deteriorates further.

Educational use only. This tool performs correct arithmetic but is not a medical device. All processing is local — no data is sent to any server.