Enter your patient's Mean Arterial Pressure (MAP) and Intracranial Pressure (ICP) in mmHg to calculate Cerebral Perfusion Pressure (CPP) — the net pressure gradient driving blood flow to the brain. The result includes the CPP value and a clinical interpretation based on standard management thresholds.
Cerebral Perfusion Pressure (CPP)
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Clinical Interpretation
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MAP Used
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ICP Used
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Cerebral Perfusion Pressure (CPP) is the net pressure gradient that drives blood flow to the brain. It is calculated as CPP = MAP − ICP. A sufficient CPP is critical to prevent cerebral ischemia, especially in patients with brain injury or elevated intracranial pressure.
The formula is: CPP = MAP − ICP, where MAP is the Mean Arterial Pressure and ICP is the Intracranial Pressure, both measured in mmHg. This straightforward subtraction reflects the effective driving pressure for cerebral blood flow.
In healthy adults, CPP is typically maintained between 60 and 100 mmHg through a process called cerebrovascular autoregulation. Values below 50 mmHg are associated with cerebral ischemia, while values above 70 mmHg are often targeted in traumatic brain injury (TBI) management.
MAP represents the average arterial pressure during a single cardiac cycle. It can be estimated using the formula: MAP = DBP + (1/3 × (SBP − DBP)), where SBP is systolic and DBP is diastolic blood pressure. Normal MAP is approximately 70–100 mmHg.
A CPP below 50 mmHg is considered critically low and indicates inadequate cerebral perfusion, risking brain ischemia. For patients with traumatic brain injury or subarachnoid hemorrhage, current guidelines generally recommend maintaining CPP ≥ 60 mmHg.
When ICP rises — as seen in traumatic brain injury, stroke, or cerebral edema — CPP falls unless MAP is simultaneously increased. If ICP exceeds MAP, cerebral perfusion ceases entirely, which is life-threatening. Managing elevated ICP is therefore a key goal in neurocritical care.
Current Brain Trauma Foundation guidelines recommend targeting a CPP between 60 and 70 mmHg in TBI patients. The optimal value may vary by individual, and overly aggressive MAP elevation to push CPP above 70 mmHg is not generally recommended due to risk of systemic complications.
Autoregulation is the brain's ability to maintain stable cerebral blood flow across a range of perfusion pressures by dilating or constricting intracranial arteries. It is effective in healthy individuals when MAP is roughly 60–150 mmHg and ICP is around 10 mmHg. In brain-injured patients, autoregulation may be impaired, making CPP management even more critical.