Enter a blood pressure and see the MAP computed both ways, with every step shown.
Mean arterial pressure
--.-mmHg
Mean arterial pressure is the average pressure in the arteries across one full cardiac cycle. It is not the average of the systolic and diastolic numbers. At a normal resting heart rate the heart spends roughly twice as long in diastole as it does in systole, so the average sits nearer the diastolic value. That is where the 2 in front of DBP comes from in the second form.
Both formulas on this page are the standard estimates taught for a cuff pressure. A bedside monitor or an arterial line usually derives MAP from the pressure waveform itself rather than from two numbers, so a displayed MAP can differ from this arithmetic. When they disagree, the equipment's reading and your protocol decide, not this page.
A commonly cited adult range is roughly 70 to 100 mmHg. This band is repeated across general nursing and physiology references rather than fixed by one authority, and the exact figures vary between sources, so treat it as orientation and not as a threshold.
65 mmHg is a widely used target in sepsis care. The Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2026 (SCCM and ESICM) recommends an initial MAP target of 65 mmHg over higher targets for adults with septic shock, graded a strong recommendation on moderate certainty evidence. The guideline notes that holding a MAP at exactly 65 is not practical, so a reasonable range of about 5 mmHg either side is used. For adults 65 years and older it suggests a slightly lower initial range of 60 to 65 mmHg, graded conditional on low certainty evidence.
Thresholds and targets are set by the provider and by facility protocol, not by this page. A guideline number is a starting point for a population; the order in front of you governs your patient. This tool has no threshold logic in it, does not flag a result as high or low, and does not know anything about the patient.
The two forms are algebraically identical. Expanding the second one gives the first: (SBP + 2 × DBP) / 3 is the same expression as DBP + (SBP − DBP) / 3. They cannot produce different answers. If a reference and a monitor disagree on a MAP, the formula is not the reason.
Pulse pressure is already in form 1. The (SBP − DBP) in the first line is the pulse pressure, so the first form reads as the diastolic pressure plus one third of the pulse pressure. The status line under the calculator prints it.
Rounding is shown honestly. Each step is displayed to one decimal, but the result is computed from the unrounded value. That is why adding the rounded numbers on the page can land 0.1 away from the final line.
You don't have to take our word for it. Every browser has a built-in panel that shows everything a page sends or receives over the internet. On a computer (this doesn't work on a phone):