Calculates the mean arterial pressure from a blood pressure reading and shows where it sits against the 65 mm Hg target used in shock.
Result
Enter the systolic and diastolic pressure.
Sources
Surviving Sepsis 2021: Strong · 5 studies
StrongSurviving Sepsis 2021 initial MAP target of 65 mm Hg in septic shock.
5
studies
3,122
citations
40,752
PubMed papers
Evidence
Guideline recommendation
“For adults with septic shock on vasopressors, we recommend an initial target mean arterial pressure (MAP) of 65 mm Hg over higher MAP targets.”
Known limitations
In 776 patients with septic shock, targeting a MAP of 80 to 85 mm Hg instead of 65 to 70 mm Hg did not change mortality at 28 days (36.6% vs 34.0%) or 90 days. New atrial fibrillation was more common with the higher target. In the chronic hypertension subgroup, the higher target reduced renal replacement therapy, without a difference in mortality.
N Engl J Med: Journal Metrics Score 29.8, Q1 · cited 1,263 times
In 2,600 patients aged 65 or older randomized (2,463 analyzed) on vasopressors for vasodilatory hypotension, permissive hypotension (MAP 60 to 65 mm Hg) reduced vasopressor exposure; 90-day mortality was 41.0% vs 43.8% with usual care, a difference that was not statistically significant.
JAMA: Journal Metrics Score 8.7, Q1 · cited 363 times
PubMed · Free full text · DOI
In 33,330 noncardiac operations, intraoperative MAP below 55 mm Hg was associated with acute kidney injury and myocardial injury, with graded increases in risk from as little as 1 to 5 minutes below it.
Anesthesiology: Journal Metrics Score 2.6, Q1 · cited 1,522 times
In a retrospective study of 8,782 septic patients in intensive care, each unit increase in time-weighted average MAP below 65 mm Hg was associated with 11.4% higher odds of in-hospital death. Associations with death, kidney injury and myocardial injury were seen at thresholds as high as 85 mm Hg.
Intensive Care Med: Journal Metrics Score 6.4, Q1 · cited 314 times
PubMed · Free full text · DOI
In 12 patients with central aortic catheters paced at increasing heart rates, a heart-rate-corrected formula agreed with the measured MAP more closely than the standard one-third formula.
The key guideline has been cited 3,122 times, and 40,752 PubMed articles mention mean arterial pressure in their title or abstract. Citation counts from OpenAlex and article counts from PubMed, retrieved November 9, 2026. Journal Metrics Scores and quartiles are from this site’s current release; follow the journal name for details.
After the result
Below 65 mm Hg · 65 mm Hg or more · Above 100 mm Hg
Assess perfusion and the cause; confirm with an arterial line if it will change treatment. A MAP at target does not rule out shock. Judge hypertension on systolic and diastolic pressure.
Next steps
Avoid common errors
5 common errors to avoid
and 3 more
When the number misleads
1Formula vs measured MAP
An arterial line measures the mean directly and an automated oscillometric cuff estimates it from the peak oscillation; the formula is a further estimate. In one report direct arterial measurement gave 327/149 mm Hg with a MAP of 211 mm Hg, where the formula gives 208 (Al Mubaid 2026). Use the measured value when you have it.
2Fast heart rate
The formula assumes diastole fills two thirds of the cycle. At fast heart rates systole takes up more of it and the formula underestimates the true mean (Razminia 2004).
3Cuff readings in shock
The Surviving Sepsis Campaign notes that cuff estimates tend to be inaccurate, and more so in shock. For adults with septic shock it suggests invasive arterial pressure monitoring over non-invasive monitoring, as soon as practical and if resources are available (weak recommendation, very low quality of evidence).
4Wrong cuff size or position
A cuff too small for the arm reads high and one too large reads low; the arm should be at heart level. A wrong reading gives a wrong MAP.
5One number for the whole patient
A MAP of 65 mm Hg is a starting target, not proof of adequate perfusion. Patients with chronic hypertension or increased intracranial pressure may need more.
Formula
MAP = (systolic + 2 × diastolic) / 3, rounded to a whole mm Hg.
(SBP + 2 × DBP) / 3
MAP = (systolic + 2 × diastolic) / 3, rounded to a whole mm Hg.
Formula and ranges
The formula
MAP = (systolic + 2 × diastolic) / 3 = diastolic + (systolic − diastolic) / 3
The result is rounded to a whole mm Hg, the way monitors and case reports give it, and placed in a range on that rounded value.
| Result | mm Hg | Meaning |
|---|---|---|
| Very low | below 55 mm Hg | Even short periods below 55 mm Hg during surgery were linked to acute kidney injury and myocardial injury (Walsh 2013). |
| Low | 55 to 64 mm Hg | Below 65 mm Hg, the initial target recommended for adults with septic shock on vasopressors (Surviving Sepsis Campaign 2021). Outside shock, interpret against the patient’s usual pressure and symptoms. |
| Usual range | 65 to 100 mm Hg | At or above the 65 mm Hg target. Judge perfusion by the patient as well: mental state, urine output, lactate and skin. |
| High | above 100 mm Hg | High. Hypertension is diagnosed and graded on systolic and diastolic pressure, not on MAP. |
Why diastole counts twice
Heart-rate-corrected formula
Rounding
Test cases
4 published cases, each also a test case
4 published cases; the calculator reproduces every MAP.
Worked examples
An 82-year-old woman arrived in the cardiovascular intensive care unit with acute right ventricular failure after a high-risk transcatheter tricuspid valve replacement. The report gives a blood pressure of 83/52 mm Hg with a mean arterial pressure of 62 mm Hg.
“blood pressure was 83/52 mm Hg (mean arterial pressure 62 mm Hg)”
Entered as: Systolic blood pressure: 83 mm Hg; Diastolic blood pressure: 52 mm Hg.
Source: Cooper AC et al., JACC Case Rep 2026 (PubMed · Free full text · DOI)
A 76-year-old woman with multiple myeloma on chemotherapy and a purulent pericardial abscess was somnolent on arrival in the emergency department, with a blood pressure of 71/47 mm Hg. The report gives a MAP of 55 mm Hg.
“blood pressure of 71/47 mmHg, mean arterial pressure (MAP) 55 mmHg”
Entered as: Systolic blood pressure: 71 mm Hg; Diastolic blood pressure: 47 mm Hg.
Source: Pessoa AL et al., Cureus 2025 (PubMed · Free full text · DOI)
A 41-year-old man with undiagnosed severe dilated cardiomyopathy, septic shock from necrotizing fasciitis and on mechanical ventilation had a blood pressure of 82/46 mm Hg on admission; the report gives a MAP of 58 mm Hg.
“blood pressure 82/46 mmHg [mean arterial pressure (MAP) 58 mmHg]”
Entered as: Systolic blood pressure: 82 mm Hg; Diastolic blood pressure: 46 mm Hg.
Source: Chen L et al., Front Med (Lausanne) 2026 (PubMed · Free full text · DOI)
A febrile, tachycardic 33-year-old man with an intra-abdominal desmoid tumor had a blood pressure of 126/60 mm Hg; the vital signs table gives a MAP of 82 mm Hg.
Values from Table 1, vital signs at presentation.
Entered as: Systolic blood pressure: 126 mm Hg; Diastolic blood pressure: 60 mm Hg.
Source: Kozorosky E et al., Cureus 2026 (PubMed · Free full text · DOI)
FAQ
7 questions and answers
and 5 more answers
Questions
MAP = (systolic pressure + 2 × diastolic pressure) / 3, which is the same as diastolic pressure + one third of the pulse pressure. For a blood pressure of 83/52 mm Hg: (83 + 2 × 52) / 3 = 187 / 3 = 62.3, so the MAP is 62 mm Hg.
At a resting heart rate the heart spends about two thirds of each cycle in diastole, so the average pressure over the cycle sits closer to the diastolic than the systolic value. When the heart rate is fast, systole takes up more of the cycle and the formula underestimates the true mean; heart-rate-corrected formulas have been proposed for that reason (Razminia 2004).
In adults it is usually quoted as about 70 to 100 mm Hg; the calculator’s 65 to 100 range starts at the septic shock target, not at a normal value. There is no single normal value: what matters is whether organs are perfused, judged from mental state, urine output, lactate and skin. In septic shock the Surviving Sepsis Campaign recommends an initial target of 65 mm Hg for patients on vasopressors.
The Surviving Sepsis Campaign 2021 recommends an initial MAP target of 65 mm Hg over higher targets for adults with septic shock on vasopressors (strong recommendation, moderate-quality evidence). In the SEPSISPAM trial a target of 80 to 85 mm Hg did not lower mortality compared with 65 to 70 mm Hg, and in the 65 trial, permissive hypotension (MAP 60 to 65 mm Hg) in patients aged 65 or older did not increase 90-day mortality.
Not always, but it is the usual trigger for assessment. During surgery even short periods below 55 mm Hg were linked to acute kidney injury and myocardial injury (Walsh 2013), and in a retrospective study of septic patients in intensive care, greater exposure to MAP below 65 mm Hg was associated with higher odds of death and kidney injury, with associations seen at thresholds up to 85 mm Hg (Maheshwari 2018). Randomized trials have not shown benefit from higher targets. Some patients, such as those with long-standing hypertension, may need a higher pressure.
Not exactly. An arterial line measures the true mean pressure by integrating the waveform, and automated cuffs estimate the mean directly from the oscillations and calculate systolic and diastolic from it. The formula gives an estimate from two numbers, so it can differ by a few mm Hg: in one report a measured MAP of 211 mm Hg came with a pressure of 327/149, for which the formula gives 208.
Pulse pressure is systolic minus diastolic pressure; MAP is the average pressure over the cardiac cycle. Two readings can have the same MAP with very different pulse pressures, for example 110/70 and 130/60 both give a MAP of 83 mm Hg.
Further reading
11 references with PubMed and DOI links
11
references
7
free full text
From Evans L et al., Crit Care Med 2021 to the newest case reports.
References
Contributed by Dr. Meng Zhao (MD · Former Neurosurgeon · Medical AI Researcher), from the original publications listed here. Last updated November 6, 2026. LinkedIn
The calculator code is tested against every worked example on this page before each release.
This calculator supports, and does not replace, clinical judgment. It is meant for healthcare professionals and is not medical advice for patients. Report an error through the contact page.
clinical grade of aneurysmal subarachnoid hemorrhage, I to V.
total calcium adjusted for albumin, in mg/dL or mmol/L.
stroke severity from 15 bedside items, 0 to 42.
eye, verbal and motor scores for preverbal children, 3 to 15.
oxygenation ratio with the Berlin ARDS severity ranges.
serum sodium corrected for high glucose, Katz or Hillier factor.
A leading critical care journal, with its current metrics.
Which published the SEPSISPAM trial, with its current metrics.