Mean Arterial Pressure Calculator
MAP, pulse pressure, and band reading from systolic and diastolic pressures.
What it does
Mean arterial pressure averages blood pressure across the whole heartbeat, weighting the resting phase double. While 120/80 names the peaks, MAP near 93 distills what organs actually feel between beats.
The tool above takes systolic with diastolic in mmHg. It returns MAP with pulse pressure and a plain band reading beside them.
The default of 120 over 80 gives MAP 93.3 mmHg with pulse pressure 40: normal range. A high 160 over 100 gives 120.0 mmHg with pulse 60, above the normal band.
The bands follow heart association pressure guidance with national library blood pressure references matching the categories. Both treat MAP below 70 as organ risk territory and one cuff reading as screening, never diagnosis.
How to use
- Enter the top systolic number from the cuff.
- Enter the bottom diastolic number.
- Read MAP first for the cycle average.
- Read pulse pressure for the beat to rest gap.
- Read the band, then repeat readings before acting.
Formula
- systolic
- Peak pressure during the beat.
- diastolic
- Resting pressure, doubled in the average.
- 70-100
- Normal MAP band in mmHg.
Diastole dominates the cycle in time, hence the double weight. Cuff position, talking, and crossed legs each add several points of noise, so sit still and repeat.
Worked example
Example: 120 over 80
Defaults: systolic 120, diastolic 80.
- Double diastole: 2 x 80 = 160.
- Add systolic: 120 + 160 = 280.
- Divide: 280 / 3 = 93.3 mmHg.
- Pulse: 120 - 80 = 40 mmHg.
- Tool shows 93.3 mmHg, 40 mmHg, Normal range.
Reference table
| Reading | MAP | Band |
|---|---|---|
| 120 / 80 | 93.3 mmHg | Normal range |
| 90 / 60 | 70.0 mmHg | Normal range |
| 140 / 90 | 106.7 mmHg | High: above the normal band |
Limits
- Screening only; diagnosis needs repeated clinical readings.
- Cuff size and position shift results several points.
- Exercise, caffeine, and stress spike single readings.
- Arrhythmias break the averaging assumptions.
Common mistakes
- Averaging systolic and diastolic evenly instead of doubling diastole.
- Acting on one excited reading.
- Measuring over sleeves or with legs crossed.
- Reading diastolic above systolic without noticing the swap.
- Chasing MAP while ignoring very high systolic peaks.
Try it yourself
Quick checks. Answers sit tucked under each question.
160 over 100?
(160 + 200) / 3 = 120.0 mmHg, pulse 60: high band.
Systolic below diastolic entered?
Rejected: systolic must read above diastolic.
Why double diastole?
The heart rests about twice as long as it beats each cycle.
Questions
What is MAP?
The cycle averaged arterial pressure: (systolic + 2 x diastolic) / 3.
What is normal MAP?
About 70 to 100 mmHg. Below 60 to 65 organs suffer.
Why does MAP matter?
Organs feel the average, not the peaks. ICU care often targets MAP directly.
What is pulse pressure?
Systolic minus diastolic. Near 40 is typical; wide gaps flag stiff arteries.
Can one reading diagnose?
No. Sit five minutes, repeat twice, and average before any conclusion.
Does MAP replace 120/80?
No, it compresses the pair into one perfusion number beside the familiar reading.