Mean Arterial Pressure
MAP = DBP + 1/3 × (SBP - DBP). The formula approximates the average arterial pressure throughout the cardiac cycle. The calculator shows both the formula and the worked substitution with your values.
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About MAP Calculator
Manual SBP/DBP entry, instant MAP, pulse pressure, Shock Index, and SOFA cardiovascular reference.
manual inputformula visiblemmHg / kPaShock Indexsession history
About this calculator
What this does
Calculates mean arterial pressure (MAP) from systolic and diastolic blood pressure using the standard formula MAP = DBP + 1/3(SBP - DBP). Also computes pulse pressure, Shock Index (when heart rate is provided), maps the result to a reference band (normal, low, or critical), and surfaces SOFA cardiovascular criteria when relevant.
Who it is for
Healthcare professionals, medical students, nurses, paramedics, and anyone in a clinical or educational setting who needs to quickly evaluate hemodynamic status from blood pressure readings with worked formula display and reference thresholds.
How it works
Enter the systolic and diastolic pressures in mmHg or kPa. The calculator instantly displays MAP, pulse pressure, the worked formula substitution, and a reference band. Optionally enter heart rate to calculate Shock Index and save the reading to the session history (stored in browser storage for the current session).
Limitations
The MAP formula is an approximation that assumes a normal heart rate and vascular tone. It may be less accurate in patients with extreme tachycardia, bradycardia, or aortic valve abnormalities. Shock Index is a screening tool for hemodynamic instability, not a substitute for comprehensive clinical assessment. Session history is stored in sessionStorage and is cleared when the browser tab is closed.
Formula
Pulse Pressure
Pulse pressure = SBP - DBP. This represents the difference between systolic and diastolic pressure and is an indicator of arterial stiffness and cardiac output. Normal pulse pressure is around 40 mmHg.
Shock Index
SI = HR / SBP. A Shock Index above 1.0 may indicate hemodynamic instability or compensated shock. The calculator computes this automatically when heart rate is entered. Note: SI uses the original SBP value, not MAP.
Unit Conversion
mmHg to kPa: multiply mmHg × 0.133322. kPa to mmHg: multiply kPa × 7.50062. The calculator converts both SBP and DBP when the unit toggle is switched, keeping the MAP calculation aligned with the chosen unit.
How it works
Step 1
Enter SBP and DBP
Type the systolic and diastolic pressures exactly as measured.
Step 2
Pick the unit
Use mmHg or kPa, and switch only if your source reading uses the other unit.
Step 3
Read the result
Review MAP, pulse pressure, the worked formula, and the active reference band.
Step 4
Open clinical tools only if needed
Use the collapsed Shock Index and history block when you want a bedside follow-up view.
Reference ranges
Normal MAP
70–100 mmHg is the generally accepted normal range for adults. Values above 60 mmHg are typically needed to perfuse vital organs. The calculator marks 65–100 mmHg as the standard reference band.
Low MAP (60–69 mmHg)
MAP in this range indicates reduced organ perfusion pressure and may require clinical attention. The calculator labels this as a low-MAP band distinct from critical values, helping clinicians identify borderline cases quickly.
Critical MAP (below 60 mmHg)
MAP below 60 mmHg is considered critical and is typically associated with inadequate tissue perfusion and organ failure risk. This threshold triggers the SOFA cardiovascular reference note in the result.
Pulse Pressure
Normal pulse pressure is 30–50 mmHg. Wide pulse pressure (>60 mmHg) may suggest aortic regurgitation, atherosclerosis, or hyperthyroidism. Narrow pulse pressure (<30 mmHg) may indicate cardiac tamponade, heart failure, or hypovolemia.