Mean Arterial Pressure Calculator
A blood pressure reading of 120/80 mmHg gives an estimated mean arterial pressure of 93.3 mmHg. This mean arterial pressure calculator uses systolic and diastolic blood pressure to estimate MAP with the standard resting approximation. It is a quick cuff-reading estimate for learning and general tracking, not medical advice or a diagnosis.
Quick answer
MAP is estimated here as diastolic pressure plus one-third of pulse pressure.
What this tells you
- •MAP is estimated here as diastolic pressure plus one-third of pulse pressure.
- •Pulse pressure is systolic pressure minus diastolic pressure.
- •The result usually falls between the diastolic and systolic numbers.
- •This shortcut works best as a quick resting estimate from cuff readings.
How to Use
- 1Enter the systolic blood pressure, which is the top number from your reading.
- 2Enter the diastolic blood pressure, which is the bottom number from your reading.
- 3Calculate to see the estimated mean arterial pressure and pulse pressure.
- 4If you are tracking readings, compare repeated seated measurements instead of relying on one rushed reading.
How It Works
Formula
Pulse pressure = systolic pressure - diastolic pressure
MAP = diastolic pressure + (pulse pressure / 3)
Equivalent form: MAP = (systolic pressure + 2 x diastolic pressure) / 3This calculator uses the standard bedside approximation for a cuff blood pressure reading. It assumes the heart spends more time in diastole than systole during a typical resting rhythm, so the diastolic value gets twice the weight of the systolic value.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Common adult reading
Pulse pressure is 120 - 80 = 40. MAP = 80 + (40 / 3) = 93.3 mmHg after rounding.
Lower reading example
Pulse pressure is 30, so the estimate is 60 + 10 = 70 mmHg.
Common mistakes
- Typing the diastolic number higher than the systolic number
- Treating one cuff reading as more important than repeat measurements taken at rest
- Using the estimate as a diagnosis or treatment decision by itself
Limitations
This calculator uses the common cuff-reading approximation only. It does not use invasive arterial monitoring, repeated averaging, abnormal heart rhythm adjustments, exercise readings, shock states, vasoactive medications, arterial stiffness, or cuff-size error checks. MAP can differ from this estimate when the blood pressure reading itself is inaccurate or the clinical situation is unstable.