BP MAP Calculator — Mean Arterial Pressure from SBP/DBP
Quick start: Enter systolic (SBP) and diastolic (DBP) pressures in mmHg. The tool returns Mean Arterial Pressure (MAP) in mmHg.
Definition
Mean Arterial Pressure (MAP) is the average arterial pressure across one cardiac cycle, weighted by the longer diastolic phase. It is a proxy for tissue perfusion at the arterial level.
How It Works
- Inputs (required): SBP and DBP in mmHg; SBP must be greater than DBP.
- Computation: The calculator applies a diastolic-weighted average.
- Output: MAP in mmHg with one decimal; displayed instantly once inputs are valid.
Formula
MAP = (SBP + 2 × DBP) ÷ 3
Variables: SBP = systolic blood pressure (mmHg); DBP = diastolic blood pressure (mmHg).
Worked Example
Given: SBP = 120 mmHg, DBP = 80 mmHg
MAP = (SBP + 2 × DBP) ÷ 3
= (120 + 2 × 80) ÷ 3
= (120 + 160) ÷ 3
= 280 ÷ 3
= 93.3 mmHg
Rounded to one decimal: 93.3 mmHg. For consistency, the calculator uses en-US formatting (e.g., 93.3; thousands with commas if applicable).
Applications
- Screening perfusion status in routine vitals when only SBP/DBP are available.
- Contextualizing BP categories with a single mean value (mmHg).
- Tracking trends over time during lifestyle or medication changes.
Assumptions & Limitations
- Resting, seated measurements; cuff size appropriate; avoid caffeine/exercise 30 minutes prior.
- Formula assumes a normal heart rate and rhythm; it approximates diastolic dominance.
- Not for critical care titration; invasive or advanced methods may be required there.
- Measurement error ±3–5 mmHg per device and technique is common; average multiple readings.
Tips & Common Mistakes
- SBP must be greater than DBP; if not, remeasure.
- Use mmHg only; do not convert to kPa here.
- Take two to three readings one minute apart; compute the average SBP and DBP before MAP.
Note: This is educational and for general planning. It does not replace clinical evaluation or individualized medical judgment.