Mean Arterial Pressure (MAP) Calculator
Calculate mean arterial pressure (MAP) from systolic and diastolic blood pressure. Instantly see your MAP and normal-range category.
How to use this tool
- Enter systolic bp and diastolic bp in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your mean arterial pressure and the full breakdown beneath it.
Educational estimate — not medical advice. Consult a clinician.
Mean arterial pressure (MAP) represents the average pressure in your arteries during one cardiac cycle: MAP = (SBP + 2 × DBP) ÷ 3. A MAP of 70–100 mmHg is generally considered normal for adults at rest.
Formula
MAP = (Systolic BP + 2 × Diastolic BP) ÷ 3
This is equivalent to Diastolic BP + (Pulse Pressure ÷ 3), where Pulse Pressure = Systolic − Diastolic.
How it works
Mean Arterial Pressure (MAP) is calculated as a weighted average of systolic and diastolic blood pressure, giving diastolic twice the weight because the heart spends roughly twice as long in diastole (relaxation) as in systole (contraction) at normal resting heart rates. The result is categorised as Low (<70 mmHg), Normal (70–100 mmHg), or Elevated (>100 mmHg).
MAP is a clinically important indicator because it reflects the average perfusion pressure driving blood to vital organs throughout the entire cardiac cycle. The thresholds used here are approximate physiological reference ranges; clinical decisions should always be made in conjunction with a qualified healthcare professional.
Worked example
Worked example
- Input: systolic BP = 120 mmHg, diastolic BP = 80 mmHg.
- Apply formula: MAP = (120 + 2 × 80) ÷ 3 = (120 + 160) ÷ 3 = 280 ÷ 3.
- Result: 280 ÷ 3 = 93.33 mmHg.
- Category check: 70 ≤ 93.33 ≤ 100, so category = Normal.
MAP: 93.33 mmHg (Normal)
Key terms
- Mean Arterial Pressure (MAP)
- The average blood pressure throughout one cardiac cycle; reflects the true perfusion pressure experienced by body tissues.
- Systolic pressure
- The peak blood pressure during ventricular contraction (heartbeat), the higher of the two numbers in a blood pressure reading.
- Diastolic pressure
- The blood pressure during ventricular relaxation between heartbeats, the lower of the two numbers in a blood pressure reading.
- Pulse pressure
- The difference between systolic and diastolic pressure; a wide pulse pressure can indicate arterial stiffness.
- Organ perfusion pressure
- The pressure gradient driving blood flow to an organ; adequate MAP (generally above 60–70 mmHg) is required to maintain perfusion of the kidneys, brain, and heart.
Frequently asked questions
- Why is MAP important?
- MAP is used in critical care to ensure adequate organ perfusion. A MAP below 65 mmHg may indicate shock; ICU protocols often target MAP ≥65 mmHg in sepsis management.
- Why is diastolic weighted double?
- The heart spends about two-thirds of each cardiac cycle in diastole, so diastolic pressure contributes twice as much to the average as systolic pressure in the simplified formula.
- What is a normal MAP?
- A MAP of 70–100 mmHg is widely used as the normal range for resting adults. Below 60 mmHg, vital organ perfusion becomes inadequate.