What Is Mean Arterial Pressure (MAP)?

Mean arterial pressure (MAP) is the average pressure in your arteries across one full heartbeat. It is not the simple middle of your two blood pressure numbers. Because the heart rests longer than it squeezes, MAP sits closer to the lower (diastolic) number than the higher (systolic) one.

What Mean Arterial Pressure Actually Measures

Mean arterial pressure is the average force your blood puts on artery walls during one complete cardiac cycle. That cycle includes both the squeeze (systole) and the rest (diastole). MAP blends them into one number, measured in millimeters of mercury (mmHg).

This matters because a single average reflects how well blood pushes forward into your organs. Your top and bottom numbers tell you the peak and the low point. MAP tells you the typical pressure in between, which is what tissues actually feel over time.

MAP is not the plain average of systolic and diastolic. The plain average of 120 and 80 would be 100, but the real MAP is about 93.3. The difference comes from timing, which the next section explains. You can get your own value fast with the mean arterial pressure calculator.

The MAP Formula and Why It Weights Diastolic

The short answer: MAP = DBP + (SBP – DBP) / 3, where SBP is systolic and DBP is diastolic. An equal version is MAP = (SBP + 2 x DBP) / 3. Both give the same answer, and both lean on the diastolic number.

Why the lean toward diastolic? Your heart spends about two-thirds of each cycle resting in diastole and only about one-third squeezing in systole. The formula mirrors that split, counting the diastolic pressure twice as much as the systolic pressure. That is the idea behind the one-third and two-thirds weighting.

The piece in parentheses, SBP minus DBP, is your pulse pressure. The formula takes one-third of that gap and adds it to the diastolic floor. So MAP always lands above diastolic but well below systolic, by design.

A Worked Example You Can Check By Hand

Take a textbook reading of 120/80 mmHg. Here is the math, one line at a time, so you can follow every step. Systolic (SBP) is 120 and diastolic (DBP) is 80.

1. Find the pulse pressure. Subtract diastolic from systolic: 120 – 80 = 40 mmHg.
2. Take one-third of it. Divide 40 by 3: 40 / 3 = about 13.3 mmHg.
3. Add the diastolic floor. Add 80: 80 + 13.3 = 93.3 mmHg.

So a 120/80 reading gives a MAP of about 93.3 mmHg and a pulse pressure of 40 mmHg. Notice the MAP sits well below the plain midpoint of 100. That gap is the one-third weighting at work.

Try a second reading of 140/90. Pulse pressure is 140 – 90 = 50. One-third of 50 is about 16.7. Add the diastolic 90, and MAP is about 106.7 mmHg. The same three steps work for any pair of numbers.

What the MAP Number Means for Perfusion

MAP matters because it drives perfusion, the delivery of oxygen-rich blood to your organs. A very low MAP can mean tissues are not getting enough blood. The number is a general reference point, not a personal target or a diagnosis.

A MAP of about 70 to 100 mmHg is commonly cited as a typical adult range. Clinicians often reference a MAP of at least about 65 mmHg as the level thought to perfuse vital organs. These are general figures. The right number for any person depends on their health and clinical situation.

Our 120/80 example gives a MAP near 93.3 mmHg, which falls inside that typical band. Still, a single reading is just a snapshot. Only a qualified health professional can judge what a MAP means for you.

MAP vs Systolic, Diastolic, and Pulse Pressure

Your blood pressure reading packs several numbers into one slash. Systolic is the peak when the heart squeezes. Diastolic is the low point when it rests. Pulse pressure is the gap between them, and MAP is the weighted average across the whole beat.

These numbers answer different questions, so they are not interchangeable. The table lines up all four for a 120/80 reading, so you can see how they relate.

For the standard categories behind the systolic and diastolic numbers, see our guide on blood pressure categories explained. For a lifestyle factor that can shift those numbers, read sodium and blood pressure.

Common Questions and Cautions About MAP

MAP is a useful average, but it does not replace the full reading. Two people can share a MAP yet have very different systolic and diastolic numbers. The gap between those numbers, your pulse pressure, carries its own meaning that MAP alone hides.

The formula here is an estimate that works best at normal heart rates. At very fast heart rates, the heart spends less time in diastole, so the simple one-third rule is less exact. Monitors in a hospital measure MAP directly rather than estimating it.

Treat every MAP figure in this article as general education. The typical range and the ~65 reference are population-level signposts, not personal goals. Any decision about your blood pressure belongs to a qualified health professional who knows your history.

FAQs About Mean Arterial Pressure

Sources and Further Reading

This article is general education, not medical advice. The numbers here are general guidance, not personal targets. Talk to a healthcare provider about your own health. Reviewed for accuracy by Dr. Abdullah Khalil, MBBS. Last updated 2026-10-05.