Mean Arterial Pressure Calculator
Estimate your mean arterial pressure from a blood pressure reading — for learning, not diagnosis.
MAP = diastolic + (systolic − diastolic) / 3. A MAP of about 70–100 mmHg is generally considered enough to perfuse the organs. If you entered a diastolic higher than the systolic, the result is blank — double-check which is which.
This is an educational estimate, not medical advice. Numbers here can't diagnose or rule out any condition. Talk to a qualified clinician about your own health.
How it works
Your blood pressure reading has two numbers: the systolic (the higher one, when your heart squeezes) and the diastolic (the lower one, when it relaxes). Mean arterial pressure is a single number that tries to capture the average pressure pushing blood through your arteries across a full heartbeat.
Because the heart spends more of each beat relaxed than contracting, MAP sits closer to the diastolic number. The common estimate is MAP = diastolic + (systolic − diastolic) ÷ 3. For a reading of 120 over 80, that's 80 + 40/3, which comes out to about 93 mmHg.
A MAP of roughly 70 to 100 mmHg is generally considered enough to keep the organs supplied with blood. This calculator is a quick way to see the number, but a real reading depends on how and when your pressure was measured — one figure on a screen doesn't tell the whole story.
Frequently asked questions
What's a normal mean arterial pressure?
Roughly 70 to 100 mmHg is the range usually described as adequate for perfusing the body's organs. Below about 60 mmHg, organs may not get enough blood flow. This tool is educational — a clinician interprets your numbers in context.
Why is MAP weighted toward the diastolic number?
During each heartbeat the heart spends about two-thirds of the time relaxed (diastole) and one-third contracting (systole). The one-third formula reflects that timing, which is why MAP lands closer to the lower diastolic value than the midpoint.
Is this formula exact?
No, it's an approximation that works reasonably well at normal heart rates. True MAP is the average of the pressure waveform over a full beat, which monitors measure directly. At very high or low heart rates the simple formula drifts, so treat the result as an estimate.