What is my mean arterial pressure?
Enter a systolic and a diastolic blood pressure to estimate the mean arterial pressure (MAP) and the pulse pressure, or enter any two of the four to find the others. For information only. This is not medical advice or a diagnosis. Do not use it to make treatment decisions without a clinician. No licensed clinician has reviewed this page.
- Mean arterial pressure
- 93.3 mmHg
A blood pressure of 120 mmHg/80 mmHg gives a mean arterial pressure of 93.3 mmHg.
- Pulse pressure
- 40 mmHg
Mean arterial pressure: 93.3 mmHg. A blood pressure of 120 mmHg/80 mmHg gives a mean arterial pressure of 93.3 mmHg.
This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use
How to calculate
Estimates mean arterial pressure (MAP) from systolic and diastolic blood pressure as the diastolic pressure plus one third of the pulse pressure, or solves for any of the four from two.
Example with the default inputs (Systolic (top number) 120 mmHg, Diastolic (bottom number) 80 mmHg): A blood pressure of 120 mmHg/80 mmHg gives a mean arterial pressure of 93.3 mmHg.
Formula: MAP = DBP + (SBP − DBP) ÷ 3; pulse pressure = SBP − DBP.
- The formula weights the diastolic pressure two thirds and the systolic one third, because at a resting heart rate diastole lasts about two thirds of each heartbeat.
- At fast heart rates systole takes a larger share of each beat, and the formula underestimates the true mean pressure (Razminia 2004).
- This is an estimate from a cuff reading, for information only; it is not a measured arterial pressure and not medical advice.
Worked examples
Each example is checked against the calculator on every build.
- Systolic (top number) 120 mmHg, Diastolic (bottom number) 80 mmHg gives Mean arterial pressure 93.3 mmHg, Pulse pressure 40 mmHg.Source: MAP = DBP + (SBP − DBP) ÷ 3 (Razminia 2004; Meaney 2000): 80 + 40 ÷ 3 = 93.3 mmHg
- Systolic (top number) 140 mmHg, Diastolic (bottom number) 90 mmHg gives Mean arterial pressure 106.7 mmHg.
- Mean arterial pressure 65 mmHg, Diastolic (bottom number) 50 mmHg gives Systolic (top number) 95 mmHg.
- Mean arterial pressure 100 mmHg, Pulse pressure 45 mmHg gives Diastolic (bottom number) 85 mmHg, Systolic (top number) 130 mmHg.
Medical disclaimer
This calculator is for information and education only. It is not medical advice, and its result is not a diagnosis. Do not use it to start, stop, or change a treatment without a clinician who knows your health history. No licensed clinician has reviewed this page. This site's editors checked the formulas and worked examples against published sources. If you think you have a medical emergency, call your local emergency number.
When this does not apply. The one-third formula estimates the mean of a cuff reading in adults at a resting heart rate. It underestimates the true mean at fast heart rates, when systole takes a larger share of each beat (Razminia and others, 2004, who compared it with pressures measured in the aorta during cardiac catheterization). It is not a measured arterial pressure: in intensive care, MAP comes from an arterial line. Readings outside 50 to 300 mmHg systolic and 20 to 200 mmHg diastolic give no answer.
How it works
With the systolic pressure SBP, the diastolic pressure DBP, the mean arterial pressure MAP and the pulse pressure PP:
- MAP = DBP + (SBP − DBP) ÷ 3
- PP = SBP − DBP
- so MAP = DBP + PP ÷ 3
Enter any two of the four and the calculator finds the other two, with these rearrangements:
- from SBP and DBP: MAP = DBP + (SBP − DBP) ÷ 3, PP = SBP − DBP;
- from SBP and MAP: DBP = (3 × MAP − SBP) ÷ 2;
- from DBP and MAP: SBP = 3 × MAP − 2 × DBP;
- from SBP and PP: DBP = SBP − PP; from DBP and PP: SBP = PP + DBP;
- from MAP and PP: DBP = MAP − PP ÷ 3, then SBP = DBP + PP.
Pressures may be typed in mmHg or kPa (1 mmHg = 13.5951 × 9.80665 Pa = 133.322 Pa). Allowed ranges: systolic 50 to 300 mmHg, diastolic 20 to 200, MAP 20 to 250, pulse pressure above 0 up to 250. A solved value outside its range, such as a diastolic pressure above the systolic (a pulse pressure of 0 or less), gives no answer. MAP and pulse pressure are shown to one decimal place; nothing is rounded before that.
Rounding. Results are shown rounded half up from the decimal value, so a pulse pressure of 92.15 − 67.4 = 24.75 mmHg shows as 24.8, and a MAP of 111.65 as 111.7. A computer’s arithmetic can leave a result such as 31.5 stored as 31.499999999999996, so each result is first rounded to 12 significant digits, which gives back the decimal value, and is then shown rounded half up. The pressures are kept in mmHg to that decimal value, whatever unit you type.
Assumptions
- Diastole lasts about two thirds of each heartbeat, as at a resting heart rate.
- The readings come from a correctly sized cuff, with the person seated and rested.
- The result is an estimate for education. It is not medical advice.
Worked examples by hand
120/80 mmHg. MAP = 80 + (120 − 80) ÷ 3 = 80 + 13.33 = 93.3 mmHg; pulse pressure = 40 mmHg.
140/90 mmHg. MAP = 90 + 50 ÷ 3 = 106.7 mmHg.
A MAP of 65 with a diastolic pressure of 50. SBP = 3 × 65 − 2 × 50 = 95 mmHg.
A MAP of 100 with a pulse pressure of 45. DBP = 100 − 45 ÷ 3 = 85 mmHg; SBP = 85 + 45 = 130 mmHg.
Other questions people ask
What is mean arterial pressure?
The average pressure in the arteries over one heartbeat. It is closer to the diastolic (bottom) number than to the systolic (top) number, because the heart spends about two thirds of each beat relaxing.
How do I calculate MAP by hand?
Take the diastolic pressure and add one third of the pulse pressure (systolic minus diastolic). For 120/80: 80 + (120 − 80) ÷ 3 = 80 + 13.3 = 93.3 mmHg.
What is pulse pressure?
The systolic pressure minus the diastolic pressure. For 120/80 it is 40 mmHg. It is the rise in pressure with each heartbeat.
Why is the formula only an estimate?
The one-third weighting assumes diastole takes about two thirds of each beat, which fits resting heart rates. When the heart beats fast, systole takes a larger share, and the formula underestimates the true mean (Razminia and others, 2004). In hospital, MAP can be measured directly with an arterial line.
Can I find the systolic pressure from the MAP?
Yes. Rearranged, SBP = 3 × MAP − 2 × DBP. With a MAP of 65 and a diastolic pressure of 50: 3 × 65 − 2 × 50 = 95 mmHg. The calculator solves for any value from any two others.
Can I use kilopascals?
Yes. Pick kPa in the unit list. The calculator converts with 1 mmHg = 0.133322 kPa (the conventional millimetre of mercury, 13.5951 g/cm³ × 9.80665 m/s²).