Pulse Pressure Calculator
Pulse gap, MAP, and band from BP readings.
What it does
Pulse pressure is the gap between beats. Systolic pushes while diastolic rests, and the gap reflects stroke volume against vessel stiffness. A 120 over 80 pair gives 40, while 160 over 70 gives 90 for very different reasons.
The tool above subtracts diastolic from systolic and adds MAP beside it. Defaults give 40 mmHg pulse with 93.3 mmHg MAP and Normal pulse pressure. A 140 over 90 pair gives 50 with 106.7 MAP, still normal by gap while higher overall. Wide gaps deserve review even when diastolic looks calm.
Context separates athletes from illness. Young fit people can show narrow gaps at rest, while older adults often widen with stiff conduit vessels. Fever, anemia, and valve leaks also move the number, so one cuff reading never stands alone.
This page grades information only. It does not diagnose hypertension, shock, or valve disease. Concerning readings need repeats plus clinical review.
How to use
- Enter the systolic number.
- Enter the diastolic number.
- Read pulse pressure first.
- Read MAP for perfusion context.
- Read the band verdict.
- Average two seated repeats before judging.
Formula
- sys
- Peak arterial pressure in mmHg.
- dia
- Lowest arterial pressure in mmHg.
- MAP
- Mean perfusion pressure estimate.
Brachial cuff readings in mmHg. At systolic at or below diastolic there is no gap to grade. Arrhythmia and cuff errors distort single readings, so average repeats.
Worked example
Example: 120 over 80
Defaults: 120 systolic with 80 diastolic. Single readings vary, so average repeats.
- Inputs: 120 over 80 mmHg.
- Pulse: 120 minus 80 is 40 mmHg pulse.
- MAP: 80 plus 40 / 3 is 93.3 mmHg MAP.
- Band: 40 sits in 40 to 60, so Normal pulse pressure.
- A 160 over 70 case gives 90 wide. Tool shows the same three outputs.
Reference table
| Reading | Pulse | MAP |
|---|---|---|
| 120 over 80 | 40 mmHg pulse | 93.3 mmHg MAP |
| 140 over 90 | 50 mmHg pulse | 106.7 mmHg MAP |
| 160 over 70 | 90 mmHg pulse | 100 mmHg MAP |
| 110 over 70 | 40 mmHg pulse | 83.3 mmHg MAP |
| 130 over 85 | 45 mmHg pulse | 100 mmHg MAP |
Limits
- Information only. No diagnosis.
- Single cuff reading noisy. Average repeats.
- Cuff size and arm matter. Errors common.
- No rhythm or valve modeling.
Common mistakes
- Reading one spike as baseline.
- Wrong cuff size shifting numbers.
- Ignoring diastolic while chasing systolic.
- Comparing arms without repeating.
- Acting on a single wide gap alone.
Try it yourself
Quick checks. Answers sit tucked under each question.
140 over 90?
Pulse is 50 mmHg with MAP 106.7 mmHg. Normal pulse pressure.
160 over 70?
Pulse is 90 mmHg with MAP 100 mmHg. Wide pulse pressure, discuss with a clinician.
Questions
How is pulse pressure figured?
Systolic minus diastolic. Here 40 mmHg pulse.
How is MAP figured?
Diastolic plus one third of pulse. Here 93.3 mmHg MAP.
What counts as normal?
40 to 60 normal. Here Normal pulse pressure.
What is narrow pressure?
Below 40 narrow, often low stroke volume. Confirm with repeats and care team.
What is wide pressure?
Above 60 wide, common with stiff arteries or isolated systolic rise. Here the 160 over 70 case.
Is one reading enough?
No. Cuff size, arm, rest, caffeine, and single reading noise all shift it.