Mean Arterial Pressure Calculator
Turn a blood pressure reading into mean arterial pressure (MAP), the average pressure driving blood to your organs during one heartbeat. Enter the top and bottom numbers to see MAP, pulse pressure and the blood pressure category, with the formula worked out.
How to use the Mean Arterial Pressure Calculator
- Enter the systolic pressure, the top (higher) number of your reading, in mmHg.
- Enter the diastolic pressure, the bottom (lower) number.
- Press Calculate MAP to see the mean arterial pressure and pulse pressure.
- Read the scale and category to see whether the numbers are in the usual range.
- Copy the result or compare with the table of common readings.
Mean arterial pressure formula
MAP = DBP + (SBP − DBP) ÷ 3 = (SBP + 2 × DBP) ÷ 3
- SBP = systolic blood pressure, the top number (pressure while the heart contracts)
- DBP = diastolic blood pressure, the bottom number (pressure while the heart relaxes)
- SBP − DBP = pulse pressure
Example: 130/85 mmHg gives a pulse pressure of 45 and MAP = 85 + 45 ÷ 3 = 100 mmHg.
Blood pressure categories (ACC/AHA 2017)
| Category | Systolic | Diastolic | MAP example | |
|---|---|---|---|---|
| Normal | Under 120 | and | Under 80 | 115/75 → 88 |
| Elevated | 120–129 | and | Under 80 | 125/78 → 94 |
| Stage 1 hypertension | 130–139 | or | 80–89 | 135/85 → 102 |
| Stage 2 hypertension | 140 or higher | or | 90 or higher | 150/95 → 113 |
| Hypertensive crisis | Over 180 | and/or | Over 120 | 190/120 → 143 |
For education only. Talk to a health professional about your blood pressure.
Frequently asked questions
How do you calculate mean arterial pressure?
MAP = diastolic pressure + (systolic − diastolic) ÷ 3, which is the same as (systolic + 2 × diastolic) ÷ 3. For 120/80 mmHg, MAP = 80 + 40 ÷ 3 ≈ 93.3 mmHg.
Why is diastolic pressure weighted twice as much?
At a resting heart rate the heart spends roughly two thirds of each cycle in diastole (relaxing and filling) and one third in systole, so the average pressure sits closer to the diastolic value.
What is a normal MAP?
A MAP of about 70 to 100 mmHg is generally considered normal. In hospital care a MAP of at least 60–65 mmHg is often used as the minimum needed to keep organs such as the kidneys and brain perfused.
What is pulse pressure?
Pulse pressure is systolic minus diastolic pressure. Around 40 mmHg is typical at rest. A persistently wide pulse pressure (over about 60 mmHg) is associated with stiffer arteries, especially in older adults.
Is the formula exact?
No, it is an estimate that works best at normal heart rates. Monitors with an arterial line measure MAP directly. At fast heart rates diastole is shorter, so the one-third formula underestimates MAP; the Meaney formula (DBP + 0.412 × pulse pressure) is one alternative.
Can this calculator diagnose high blood pressure?
No. Hypertension is diagnosed from repeated, properly taken readings by a health professional. This tool is for information only.