By Zencalcy Editorial TeamLast reviewed About us
Mean arterial pressure is the average pressure in the arteries during one cardiac cycle, weighted toward diastole because the heart spends more time relaxing than contracting. This calculator applies the standard MAP formula to a blood pressure reading and shows the arithmetic. It is a reference tool for understanding a number, not a diagnosis or a treatment target.
Average arterial pressure across the cardiac cycle.
MAP = (SBP + 2 × DBP) ÷ 3
The formula approximates the area under the arterial pressure waveform by weighting diastolic pressure twice. A MAP below 65 mmHg is generally treated as a sign of possibly inadequate organ perfusion, but that threshold is a clinical prompt rather than a diagnosis. Symptoms, trends and the whole clinical picture matter more than one reading.
| Symbol | Meaning |
|---|---|
| MAP | Mean arterial pressure in mmHg. |
| SBP | Systolic blood pressure in mmHg. |
| DBP | Diastolic blood pressure in mmHg. |
MAP = (120 + 2 × 80) ÷ 3 = (120 + 160) ÷ 3 = 280 ÷ 3 = 93.3 mmHg. A reading of 90/60 gives (90 + 120) ÷ 3 = 70.0 mmHg, and 70/60 gives (70 + 120) ÷ 3 = 63.3 mmHg, which falls below the usual 65 mmHg perfusion threshold.
Systolic and diastolic pressures describe the peaks and troughs of the arterial waveform, but organs are perfused by the pressure they see over the whole cycle. MAP condenses that exposure into one number, which is why critical care teams often target it when managing fluids and vasoactive drugs. The approximation works best at normal heart rates; at very fast or very slow rates the time spent in systole and diastole changes, so the fixed one-third/two-thirds weighting becomes less accurate. Even so, the formula remains a practical bedside estimate. For home use, treat MAP as a way to understand what your two readings imply together, not as a separate measurement or a reason to change medication on your own.
Continue with the Pulse Pressure Calculator, QTc Calculator, or the CHA2DS2-VASc Calculator — or browse more cardiology tools and all health calculators.
The heart spends roughly twice as long in diastole as in systole at a normal resting rate, so the arterial pressure curve sits closer to the diastolic value for more of the cycle. Weighting DBP twice is a simple way to approximate the area under that curve.
Blood pressure, ECG and risk scores are screening aids, not diagnoses. A single reading can be misleading; trends and proper technique matter. Scores estimate population risk and do not replace clinical assessment, anticoagulation decisions or emergency care.
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Last reviewed: September 2026. See how we build and check every tool on the about page.
Content updated: September 2026