Mean Arterial Pressure Calculator
Our human physiology calculator computes mean arterial pressure accurately. Enter measurements for results with formulas and error analysis.
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
MAP = DBP + 1/3(SBP - DBP) = (SBP + 2 x DBP) / 3
Where MAP = Mean Arterial Pressure in mmHg, SBP = Systolic Blood Pressure (top number), DBP = Diastolic Blood Pressure (bottom number). The formula weights diastolic pressure by 2/3 because the heart spends approximately twice as long in diastole as in systole during each cardiac cycle.
Worked Examples
Example 1: Normal Blood Pressure
Problem:A patient has a blood pressure of 118/76 mmHg with a heart rate of 70 bpm. Calculate MAP and assess status.
Solution:MAP = DBP + 1/3(SBP - DBP)\nMAP = 76 + 1/3(118 - 76)\nMAP = 76 + 1/3(42)\nMAP = 76 + 14 = 90.0 mmHg\nPulse Pressure = 118 - 76 = 42 mmHg (normal)\nRPP = 118 x 70 = 8,260 (normal myocardial demand)
Result:MAP: 90.0 mmHg (Normal) | PP: 42 mmHg | BP: Normal | RPP: 8,260
Example 2: Stage 2 Hypertension
Problem:A patient presents with BP 162/98 mmHg and heart rate of 88 bpm. Assess cardiovascular risk.
Solution:MAP = 98 + 1/3(162 - 98)\nMAP = 98 + 1/3(64)\nMAP = 98 + 21.3 = 119.3 mmHg\nPulse Pressure = 162 - 98 = 64 mmHg (wide)\nRPP = 162 x 88 = 14,256\nMAP >110 indicates risk of organ damage. Wide PP suggests arterial stiffness.
Result:MAP: 119.3 mmHg (High) | PP: 64 mmHg | BP: Stage 2 HTN | RPP: 14,256
Frequently Asked Questions
What is Mean Arterial Pressure (MAP)?
Mean Arterial Pressure is the average pressure in the arteries during one complete cardiac cycle (heartbeat). It is not a simple average of systolic and diastolic pressures because the heart spends about two-thirds of the cycle in diastole (relaxation) and one-third in systole (contraction). Therefore, MAP is calculated as DBP + 1/3(SBP - DBP), which weights diastolic pressure more heavily. MAP is considered the primary driving pressure for organ perfusion and is more clinically significant than either systolic or diastolic pressure alone for assessing tissue blood flow.
What is pulse pressure and why does it matter?
Pulse pressure is the difference between systolic and diastolic blood pressure (SBP - DBP). Normal pulse pressure is 30-40 mmHg. A wide pulse pressure (>60 mmHg) can indicate aortic valve regurgitation, arterial stiffness (common in aging), hyperthyroidism, or increased stroke volume. A narrow pulse pressure (<25 mmHg) may suggest heart failure, aortic stenosis, cardiac tamponade, or significant blood loss. In older adults, a widening pulse pressure is an independent risk factor for cardiovascular events and is primarily caused by stiffening of the large arteries.
What is the Rate-Pressure Product?
The Rate-Pressure Product (RPP), also called the double product, is calculated as systolic blood pressure multiplied by heart rate (SBP x HR). It serves as a non-invasive estimate of myocardial oxygen consumption (how hard the heart is working). Normal resting RPP is approximately 6,000-12,000. Values above 20,000 indicate high myocardial demand and may provoke angina in patients with coronary artery disease. During exercise stress testing, an RPP above 25,000-30,000 is expected at peak effort. Medications like beta-blockers lower RPP by reducing both heart rate and blood pressure.
References
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy