Cerebral Perfusion Pressure Calculator
Cerebral perfusion pressure (CPP) is the driving pressure that delivers blood to the brain and is a key monitoring target in neurocritical care, particularly in patients with traumatic brain injury (TBI), subarachnoid hemorrhage, or other conditions causing elevated intracranial pressure (ICP). CPP is calculated by subtracting intracranial pressure from mean arterial pressure: CPP = MAP - ICP. The Brain Trauma Foundation recommends targeting CPP of 60-70 mmHg in adults with severe TBI. Enter MAP and ICP in mmHg to obtain CPP. This tool is for educational reference only; all clinical decisions require direct patient evaluation and professional judgment.
CPP formula
CPP = MAP - ICP
MAP is mean arterial pressure in mmHg. ICP is intracranial pressure in mmHg. Both must be measured in the same units and referenced to the same anatomical level (typically the tragus of the ear). The result is cerebral perfusion pressure in mmHg.
CPP interpretation
- Above 70 mmHg: Adequate perfusion for most adults. Risk of hyperemia if too high.
- 60-70 mmHg: Brain Trauma Foundation target range for severe TBI (Grade IIB recommendation).
- 50-59 mmHg: Low, risk of cerebral ischemia; reassess and consider intervention.
- Below 50 mmHg: Critical, associated with significant ischemia and poor outcome.
Frequently asked questions
What is cerebral perfusion pressure?
Cerebral perfusion pressure (CPP) is the net pressure gradient driving blood flow to the brain. It is calculated as mean arterial pressure (MAP) minus intracranial pressure (ICP). Maintaining adequate CPP is critical in traumatic brain injury and neurocritical care.
What is the normal range for CPP?
Normal CPP in adults is approximately 60-80 mmHg. The Brain Trauma Foundation recommends maintaining CPP between 60 and 70 mmHg in severe TBI to optimize outcomes. CPP below 50 mmHg is associated with cerebral ischemia.
How is mean arterial pressure (MAP) calculated?
MAP = diastolic BP + (1/3) x (systolic BP - diastolic BP). Alternatively, MAP = (SBP + 2 x DBP) / 3. Normal MAP is 70-100 mmHg. This calculator accepts MAP directly; if you need MAP from blood pressure values, use a dedicated MAP calculator.
How is intracranial pressure measured?
ICP is typically measured invasively via an intraventricular catheter (gold standard) or intraparenchymal probe. Normal ICP is 5-15 mmHg in adults. ICP above 20-25 mmHg is considered elevated and may require treatment.
What treatments are used when CPP is too low?
When CPP falls below target, interventions include raising MAP with vasopressors, reducing ICP with osmotherapy (mannitol or hypertonic saline), hyperventilation for acute herniation, and CSF drainage. The approach depends on the clinical situation and underlying pathology.
Official sources
- Brain Trauma Foundation: Guidelines for the Management of Severe TBI.
- NIH National Institute of Neurological Disorders and Stroke: Traumatic Brain Injury.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.