MM HG to PSI
Convert millimeters of mercury into psi for gauges, specs, hydraulic notes, and pressure reference checks.
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MM HG to PSI Table
| Millimeters of Mercury | PSI |
|---|---|
| 1 | 0.019336775 |
| 5 | 0.096683874 |
| 10 | 0.193367747 |
| 25 | 0.483419368 |
| 50 | 0.966838735 |
| 100 | 1.93367747 |
| 250 | 4.834193675 |
| 500 | 9.66838735 |
| 1,000 | 19.3367747 |
| 2,500 | 48.34193675 |
Popular Conversions
- 1 millimeters of mercury = 0.019336775 psi
- 5 millimeters of mercury = 0.096683874 psi
- 10 millimeters of mercury = 0.193367747 psi
- 25 millimeters of mercury = 0.483419368 psi
- 50 millimeters of mercury = 0.966838735 psi
- 100 millimeters of mercury = 1.93367747 psi
- 250 millimeters of mercury = 4.834193675 psi
- 500 millimeters of mercury = 9.66838735 psi
What is Millimeters of Mercury and PSI?
Millimeters of Mercury
Definition: Millimeters of mercury express pressure using the height of a mercury column.
History/origin: The unit comes from classic barometers and medical manometers that measured pressure as a fluid height.
Current use: MmHg is used in blood pressure, vacuum work, laboratory pressure readings, and older engineering references.
PSI
Definition: PSI means pounds per square inch and is a customary pressure unit.
History/origin: It became a standard engineering and industrial unit in US customary practice.
Current use: PSI is used in hydraulics, pneumatics, tires, compressors, and pressure gauges.
Related Pressure Conversions
Pressure values are commonly translated across SI, customary, and fluid-column units in the same job.
| Related Conversion | Factor or Rule | Formula |
|---|---|---|
| mmHg to kPa | × 0.133322387 | kPa = mmHg × 0.133322387 |
| MPa to psi | × 145.037738 | psi = MPa × 145.037738 |
| Pa to kPa | ÷ 1,000 | kPa = Pa ÷ 1,000 |
| Pa to psi | × 0.000145037738 | psi = Pa × 0.000145037738 |
| psi to bar | × 0.068947573 | bar = psi × 0.068947573 |
| psi to mmHg | × 51.714933 | mmHg = psi × 51.714933 |
| psia to psig | minus atmosphere | psig = psia – atmospheric pressure |
| psig to psia | plus atmosphere | psia = psig + atmospheric pressure |
Typical Use Cases
Frequently Asked Questions
Q: Why do pressure pages like MM HG to PSI change the number so much?
A: Pressure units are sized very differently, so the same physical pressure can need a much larger or much smaller number after conversion.
Q: What does 1 millimeters of mercury become in psi?
A: 1 millimeters of mercury equals 0.019336775 psi, which is a helpful checkpoint for tire pressure, hydraulics, vacuum work, and process instrumentation.
Q: When should I keep the original pressure unit?
A: Keep it when the sensor, regulator, gauge, or specification you are reading already uses that unit. Convert only when the destination document or tool expects another scale.
Q: Why do some pressure answers become decimals while others become large integers?
A: That is simply the size difference between the unit systems involved. The physical pressure stays the same.
Q: How do I convert PSI back into Millimeters of Mercury?
A: mmHg = psi ÷ 0.0193367747. That reverse relationship is useful when the reading already starts in the target pressure unit.
Q: Is this exact or approximate?
A: The calculation uses an exact factor.