Heart & circulation
Mean arterial pressure (MAP) calculator
Enter a systolic and diastolic blood pressure reading to calculate the mean arterial pressure (MAP), the average pressure in your arteries over one heartbeat, along with the pulse pressure. A MAP of 70 to 100 mmHg is the range generally considered normal.
Enter your values above to see your result and what it means.
How to calculate mean arterial pressure
The standard MAP formula is MAP = diastolic + (systolic - diastolic) / 3. The heart spends longer relaxing than contracting in each beat, so the average pressure sits closer to the diastolic number than a simple midpoint would. For a reading of 120/80, the pulse pressure is 120 - 80 = 40, one third of that is 13.3, and the MAP is 80 + 13.3 = 93 mmHg.
| Blood pressure | Pulse pressure | MAP |
|---|---|---|
| 100/60 mmHg | 40 mmHg | 73 mmHg |
| 110/70 mmHg | 40 mmHg | 83 mmHg |
| 120/80 mmHg | 40 mmHg | 93 mmHg |
| 130/85 mmHg | 45 mmHg | 100 mmHg |
| 140/90 mmHg | 50 mmHg | 107 mmHg |
| 160/100 mmHg | 60 mmHg | 120 mmHg |
What is a normal MAP?
MAP in adults is generally considered normal between 70 and 100 mmHg. The lower threshold for concern is around 60 mmHg, the level below which organs may not receive enough blood. In intensive care, guidelines for septic shock set an initial MAP target of 65 mmHg. Those hospital numbers describe very ill people on monitors; for everyone else, MAP is mostly a convenient summary of a blood pressure reading.
| MAP | Range | Context |
|---|---|---|
| Below 60 mmHg | Very low | Usual lower threshold for concern about organ blood flow |
| 60 to 69 mmHg | Low | Under the usual range; 65 mmHg is the initial target in septic shock |
| 70 to 100 mmHg | Normal | Range generally considered normal in adults |
| Above 100 mmHg | High | Goes with raised systolic or diastolic pressure |
Why doctors use MAP
MAP is the pressure that pushes blood into the organs, so in hospital it is a better guide to how well the brain, heart and kidneys are supplied than the systolic number alone. Outside hospital, guidelines classify blood pressure by systolic and diastolic values, and MAP adds little to a routine home reading.
Pulse pressure
Pulse pressure is the difference between the systolic and diastolic numbers, 40 mmHg for a reading of 120/80. The calculator shows it because it is the middle step of the MAP formula, and because doctors sometimes look at it alongside the reading itself.
Frequently asked questions
What is the formula for mean arterial pressure?
MAP = diastolic pressure + one third of the pulse pressure, where pulse pressure is systolic minus diastolic. Written out: MAP = DBP + (SBP - DBP) / 3. Some researchers multiply the pulse pressure by 0.412. Against direct measurement that version runs about 1 mmHg high on average and the standard formula about 2 mmHg low, a difference that rarely matters.
What is a normal MAP?
Between 70 and 100 mmHg is the range generally considered normal. A reading of 120/80 gives a MAP of about 93 mmHg.
What MAP is too low?
Below about 60 mmHg, blood flow to vital organs may not be enough, which is why that level is the usual threshold for concern. In septic shock, intensive care guidelines aim for 65 mmHg or more. A low MAP from a home reading in someone who feels well is far less worrying than the same number in a hospital patient.
Is MAP the same as average blood pressure?
It is the average pressure over one heartbeat, weighted towards the diastolic number because the heart spends longer relaxing than contracting. A simple average of 120 and 80 would give 100; the MAP is about 93.
Can I calculate MAP from my home blood pressure monitor?
Yes. Enter the two numbers your monitor shows. Some automatic monitors also display a MAP of their own, calculated with the manufacturer's method, so it can differ by a few mmHg from the formula.
Sources
- DeMers D, Wachs D. Physiology, Mean Arterial Pressure. StatPearls. Treasure Island (FL): StatPearls Publishing; 2023.
- Tien LYH, Morgan WH, Cringle SJ, Yu DY. Optimal calculation of mean pressure from pulse pressure. Am J Hypertens. 2023;36(6):297-305.
- American Heart Association. Understanding Blood Pressure Readings.
- Evans L, Rhodes A, Alhazzani W, et al. Surviving Sepsis Campaign: international guidelines for management of sepsis and septic shock 2021. Intensive Care Med. 2021;47(11):1181-1247.