How to use it
- Enter the systolic pressure, the top number of the reading, in mmHg.
- Enter the diastolic pressure, the bottom number.
- Read the mean arterial pressure and the pulse pressure.
Formula
MAP = DBP + (SBP − DBP) ÷ 3 = (SBP + 2 × DBP) ÷ 3
Pulse pressure = SBP − DBP
SBP is the systolic and DBP the diastolic pressure, both in mmHg.
Worked examples
- 120/80 mmHg: MAP = 80 + 40 ÷ 3 = 93.3 mmHg; pulse pressure 40 mmHg.
- 90/60 mmHg: MAP = 60 + 30 ÷ 3 = 70 mmHg; pulse pressure 30 mmHg.
- 140/90 mmHg: MAP = (140 + 180) ÷ 3 = 106.7 mmHg; pulse pressure 50 mmHg.
Tips and common mistakes
- Swapping the two numbers is the usual slip: the systolic (top) value must be the higher one, and the calculator says so if it is not.
- One reading says little. Blood pressure changes through the day; home monitoring averages several readings taken at rest.
- This is an estimate for information, not a diagnosis. Ask a doctor about readings that worry you.