Mean Arterial Pressure Calculator
Mean arterial pressure and pulse pressure from a systolic and diastolic blood pressure reading in mmHg, with the working shown and the values in kPa too.
Result…
How it's calculated
Pulse pressure (PP) = systolic − diastolic MAP ≈ diastolic + PP ÷ 3 = (systolic + 2 × diastolic) ÷ 3 1 mmHg = 0.133322387415 kPa
Mean arterial pressure is the average pressure in the arteries over one heartbeat, the pressure that pushes blood through the organs. A common quick estimate adds one third of the pulse pressure to the diastolic pressure (StatPearls, Physiology, Mean Arterial Pressure), so the mean sits closer to the bottom number than to the top. Pulse pressure is simply the gap between the two readings. This page does the arithmetic only: it does not judge whether a reading is healthy, and one reading says little on its own.
Your numbers, step by step
About the Mean Arterial Pressure calculator
This mean arterial pressure calculator turns a blood pressure reading into two more numbers: the mean arterial pressure (MAP), an estimate of the average pressure in the arteries over one heartbeat, and the pulse pressure, the gap between the top and bottom numbers. Enter the systolic and diastolic pressures in mmHg, as a home monitor or clinic shows them, and it applies the usual estimate: the diastolic pressure plus one third of the pulse pressure. The working is shown with your numbers, and each value is also given in kilopascals for anyone who uses kPa. Students of nursing, medicine and physiology use it to check their arithmetic, and people curious about their own readings use it to understand the terms. It does the sums only and does not say whether a reading is healthy.
How to use it
- Enter the “Systolic pressure (top number)” in mmHg.
- Enter the “Diastolic pressure (bottom number)” in mmHg.
- Read the mean arterial pressure and the pulse pressure, with the values in kPa below.
- Follow the steps to see the one-third rule worked through with your reading.
Worked example
A reading of 130/85 mmHg. Pulse pressure = 130 − 85 = 45 mmHg. MAP ≈ 85 + 45 ÷ 3 = 85 + 15 = 100 mmHg, the same as (130 + 2 × 85) ÷ 3 = 300 ÷ 3. In kilopascals, the MAP is about 13.33 kPa and the pulse pressure about 6.00 kPa.
Updated
Questions people ask
How do you calculate mean arterial pressure from blood pressure?
Subtract the diastolic from the systolic to get the pulse pressure, divide it by 3 and add the result to the diastolic. For 120/80 that is 80 + 40 ÷ 3 ≈ 93 mmHg.
What is the formula for MAP?
MAP ≈ DBP + (SBP − DBP) ÷ 3, which is the same as (SBP + 2 × DBP) ÷ 3. StatPearls on mean arterial pressure gives this as a common way to estimate it.
What is pulse pressure?
It is the systolic pressure minus the diastolic pressure: 40 mmHg for a reading of 120/80. It is the part of the reading that the MAP estimate divides by 3.
What is a common mistake when working out MAP?
Taking the plain average of the two numbers. (120 + 80) ÷ 2 = 100, but the usual estimate gives about 93, because the diastolic counts twice.
Can this tell me if my blood pressure is too high or too low?
No. It only does the arithmetic, and a single reading says little on its own. Ask a doctor, nurse or pharmacist about your own readings, and seek help promptly if you feel unwell. You may also find the target heart rate calculator useful for exercise planning.