PSI to mmHg Converter
Convert PSI to mmHg for blood pressure and pressure measurements.
Result
1 psi = 51.71509578 mmHg
Results are provided for general informational purposes only. Always verify important calculations independently. Learn more
About These Units
PSI
Pounds per square inch is the imperial pressure unit.
Common Uses: US tire pressure, compressed air, plumbing, pressure washers
MMHG
Millimeters of mercury, traditionally used for blood pressure.
Common Uses: Medical blood pressure, barometers, vacuum measurements
Conversion Formula
PSI = bar × 14.5038
Worked Example:
To convert PSI to MMHG:
2 bar × 14.5038 = 29.01 PSI
Common PSI to MMHG Conversions
| PSI | MMHG | PSI | MMHG |
|---|---|---|---|
| 1 psi | 51.7151 mmhg | 50 psi | 2585.7548 mmhg |
| 2 psi | 103.4302 mmhg | 75 psi | 3878.6322 mmhg |
| 5 psi | 258.5755 mmhg | 100 psi | 5171.5096 mmhg |
| 10 psi | 517.151 mmhg | 250 psi | 12928.7739 mmhg |
| 25 psi | 1292.8774 mmhg | 500 psi | 25857.5479 mmhg |
Frequently Asked Questions
What pressure unit is used for car tires?
Car tire pressure is commonly measured in PSI (pounds per square inch) in the US, bar in Europe, and kPa in some countries like Australia and Canada. Typical passenger car tire pressure is 2.2-2.5 bar (32-36 PSI or 220-250 kPa). Always check your vehicle's specific recommendations on the door jamb sticker.
What is the difference between absolute and gauge pressure?
Absolute pressure measures total pressure including atmospheric pressure, while gauge pressure measures pressure relative to atmospheric pressure. A gauge pressure of 0 PSI means atmospheric pressure (14.7 PSI absolute). Most tire gauges and pressure equipment display gauge pressure, which is what matters for inflation and operation.
Why are there so many different pressure units?
Different pressure units evolved for specific applications and regional preferences. PSI is intuitive for imperial users, pascals are the SI standard for science, bar is convenient because it's close to atmospheric pressure, and atmospheres relate directly to sea-level conditions. Each unit serves particular industries and calculation needs.
How does altitude affect tire pressure?
As altitude increases, atmospheric pressure decreases, but the air inside your tires remains at the same absolute pressure. This means gauge pressure (what your gauge reads) appears higher at altitude. For every 1,000 feet of elevation gain, tire pressure increases by approximately 0.5 PSI due to decreased atmospheric pressure, not additional air.
What is normal atmospheric pressure?
Standard atmospheric pressure at sea level is defined as 101,325 pascals, equal to 1.01325 bar, 14.696 PSI, or exactly 1 atmosphere (atm). Weather systems cause pressure variations around this value. Low pressure (below 1000 hPa) often indicates stormy weather, while high pressure (above 1020 hPa) suggests clear conditions.
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