Mean Arterial Pressure Calculator

Mean arterial pressure (MAP) is the average pressure in your arteries over one full heartbeat. Because the heart spends roughly twice as long relaxing (diastole) as contracting (systole), MAP sits closer to the diastolic number than to the simple average of the two. Hospitals watch MAP because it reflects how well blood is pushed into organs such as the brain and kidneys. Enter a reading to get MAP, pulse pressure and the reading's blood pressure category.

How to use this tool

1. Enter the systolic (top) number from your reading in mmHg.
2. Enter the diastolic (bottom) number.
3. Optionally enter your heart rate to see the heart-rate-adjusted estimate.
4. Read MAP, pulse pressure and the ACC/AHA category for the reading.

Formula

MAP = DBP + (SBP − DBP) ÷ 3 = (SBP + 2 × DBP) ÷ 3

SBP is systolic and DBP diastolic pressure in mmHg; SBP − DBP is the pulse pressure (PP). The one-third weighting assumes a normal resting heart rate. At faster rates systole takes up a larger share of each beat, so the heart-rate-adjusted version (Razminia et al., 2004) uses MAP = DBP + (0.33 + 0.0012 × HR) × PP.

Example

A reading of 120/80 mmHg gives a pulse pressure of 40 mmHg and MAP = 80 + 40 ÷ 3 = 93.3 mmHg. With a heart rate of 72 the adjusted estimate is 80 + (0.33 + 0.0864) × 40 = 96.7 mmHg. Note that a diastolic of exactly 80 already falls in the ACC/AHA stage 1 range.