The average arterial pressure during one full heartbeat cycle, weighted toward diastolic pressure since the heart spends more time relaxed (diastole) than contracting (systole).
How it works
Diastolic pressure plus one-third of the difference between systolic and diastolic pressure gives the mean arterial pressure.
What this does not include
This does not include a health-risk classification — for categorizing a blood pressure reading, use this site’s blood pressure category calculator instead. This tool computes the MAP value itself.
How to use this calculator
- Enter your systolic and diastolic blood pressure readings.
A worked example
Blood pressure 120/80: MAP = diastolic + ⅓(systolic − diastolic) = 80 + ⅓(40) = 93.33.
Blood pressure 140/90: MAP = 106.67.
What the variables mean
| Variable | Meaning |
|---|---|
| Systolic | Pressure during heartbeats, the higher number |
| Diastolic | Pressure between beats, the lower number |
Edge cases worth knowing
MAP weights diastolic pressure more heavily than systolic — the heart spends more time in diastole (relaxed) than systole (contracted) during each cycle, which is why the formula isn’t a simple average of the two numbers.
A systolic reading lower than diastolic is physiologically invalid — systolic pressure should always exceed diastolic, so the calculator declines to show a result when that’s reversed, since it likely indicates a data entry error.
Frequently asked questions
Why is MAP weighted toward diastolic rather than a simple average?
Because the heart spends roughly twice as long in diastole (relaxed) as in systole (contracting) during each cycle, so the true time-averaged pressure sits closer to the diastolic value.
Why is MAP clinically important?
It reflects the actual perfusion pressure delivering blood to organs and tissues, which clinicians monitor closely in critical care settings.
Is MAP the same as either systolic or diastolic pressure?
No — it’s a distinct calculated value that falls between the two, closer to diastolic, representing the average pressure over the full cardiac cycle.
