Convert Millimeters of Mercury to Pounds per Square Inch
Instantly convert Millimeters of Mercury (mmHg) to Pounds per Square Inch (psi) with our free online calculator.
Formula: mmHg to psi — multiply by 0.0193367
Reference Table
| Millimeters of Mercury (mmHg) | Pounds per Square Inch (psi) |
|---|---|
| 1 | 0.0193367 |
| 5 | 0.0966836 |
| 10 | 0.193367 |
| 25 | 0.483418 |
| 50 | 0.966836 |
| 100 | 1.93367 |
How to Convert Millimeters of Mercury to Pounds per Square Inch
Formula
To convert Millimeters of Mercury (mmHg) to Pounds per Square Inch (psi): multiply by 0.0193367
Step-by-Step
- Start with your value in Millimeters of Mercury (mmHg).
- Multiply by 0.0193367 to perform the conversion.
- The result is your value expressed in Pounds per Square Inch (psi).
Conversion Factor
1 mmHg = 0.0193367 psi
Reverse Factor
1 psi = 51.7151 mmHg
Worked Example
Convert 25 Millimeters of Mercury to Pounds per Square Inch: 25 mmHg = 0.483418 psi
About Millimeters of Mercury (mmHg)
A unit of pressure historically defined as the pressure exerted by a column of mercury exactly 1 millimeter tall at the standard acceleration of gravity (9.80665 m/s²) and the standard density of mercury (13,595.1 kg/m³ at 0 °C). The mmHg's contemporary definition rounds to exactly 133.322387415 Pa (NIST SP 811). Despite being non-SI, mmHg remains the international clinical standard for blood pressure measurement ("120 over 80" mmHg) per WHO and ESH guidelines, and is the default unit for intraocular pressure in ophthalmology (normal IOP 10-21 mmHg per Glaucoma Research Foundation) and intracranial pressure monitoring in neurology. Numerically the mmHg is almost identical to the torr (1 mmHg ≈ 1.0000007 torr — the difference is whether one uses the conventional density or the experimentally measured density of mercury). Barometric atmospheric pressure was historically quoted in mmHg before kPa/hPa adoption (760 mmHg = 1 atm = 101.325 kPa).
About Pound per Square Inch (psi)
An imperial unit of pressure equal to one pound-force applied over one square inch (exactly 6,894.757 Pa per NIST SP 811). PSI is the dominant US pressure unit and remains the working unit in most US-built industrial, automotive, and consumer equipment: passenger-car tire inflation (32-35 psi cold), compressed air shop systems (typically 100-150 psi), hydraulic equipment (1,500-3,000 psi mobile, up to 10,000 psi on press brakes), ammunition chamber pressures (SAAMI specs in psi), municipal potable water supply (~40-80 psi at the meter), and natural gas distribution pressures. US engineering textbooks and the ASME B31 pipe codes, API piping specifications, and AWWA waterworks standards quote allowable pressures in psi. Engineers should distinguish gauge psi (psig — pressure above atmospheric) from absolute psi (psia — pressure above perfect vacuum); 0 psig = 14.696 psia at sea level. 1 psi = 6.895 kPa = 0.0689 bar = 51.715 mmHg.
Quick Facts
- 1 Millimeters of Mercury equals 0.0193367 Pounds per Square Inch
- 1 Pound per Square Inch equals 51.7151 Millimeters of Mercury
- Millimeters of Mercury is a unit of pressure
- Pound per Square Inch is a unit of pressure
- This conversion is commonly used in tire inflation, weather reporting, scuba diving, and engineering
- The Millimeters of Mercury belongs to the metric system
- The Pound per Square Inch belongs to the imperial system
Common Millimeters of Mercury to Pound per Square Inch Conversions
| Millimeters of Mercury (mmHg) | Pounds per Square Inch (psi) |
|---|---|
| 0.1 | 0.00193367 |
| 0.5 | 0.00966836 |
| 1 | 0.0193367 |
| 2 | 0.0386734 |
| 5 | 0.0966836 |
| 10 | 0.193367 |
| 14.696 | 0.284172 |
| 15 | 0.290051 |
| 20 | 0.386734 |
| 25 | 0.483418 |
| 50 | 0.966836 |
| 100 | 1.93367 |
| 150 | 2.90051 |
| 200 | 3.86734 |
| 500 | 9.66836 |
| 1000 | 19.3367 |
Understanding Millimeters of Mercury
The Millimeters of Mercury (symbol: mmHg) is a unit of pressure. A unit of pressure historically defined as the pressure exerted by a column of mercury exactly 1 millimeter tall at the standard acceleration of gravity (9.80665 m/s²) and the standard density of mercury (13,595.1 kg/m³ at 0 °C). The mmHg's contemporary definition rounds to exactly 133.322387415 Pa (NIST SP 811). Despite being non-SI, mmHg remains the international clinical standard for blood pressure measurement ("120 over 80" mmHg) per WHO and ESH guidelines, and is the default unit for intraocular pressure in ophthalmology (normal IOP 10-21 mmHg per Glaucoma Research Foundation) and intracranial pressure monitoring in neurology. Numerically the mmHg is almost identical to the torr (1 mmHg ≈ 1.0000007 torr — the difference is whether one uses the conventional density or the experimentally measured density of mercury). Barometric atmospheric pressure was historically quoted in mmHg before kPa/hPa adoption (760 mmHg = 1 atm = 101.325 kPa).
It belongs to the metric measurement system.
Millimeters of Mercury are commonly used in tire inflation, weather reporting, scuba diving, and engineering.
Understanding Pounds per Square Inch
The Pound per Square Inch (symbol: psi) is a unit of pressure. An imperial unit of pressure equal to one pound-force applied over one square inch (exactly 6,894.757 Pa per NIST SP 811). PSI is the dominant US pressure unit and remains the working unit in most US-built industrial, automotive, and consumer equipment: passenger-car tire inflation (32-35 psi cold), compressed air shop systems (typically 100-150 psi), hydraulic equipment (1,500-3,000 psi mobile, up to 10,000 psi on press brakes), ammunition chamber pressures (SAAMI specs in psi), municipal potable water supply (~40-80 psi at the meter), and natural gas distribution pressures. US engineering textbooks and the ASME B31 pipe codes, API piping specifications, and AWWA waterworks standards quote allowable pressures in psi. Engineers should distinguish gauge psi (psig — pressure above atmospheric) from absolute psi (psia — pressure above perfect vacuum); 0 psig = 14.696 psia at sea level. 1 psi = 6.895 kPa = 0.0689 bar = 51.715 mmHg.
It belongs to the imperial measurement system.
Pounds per Square Inch are commonly used in tire inflation, weather reporting, scuba diving, and engineering.
Why Convert Millimeters of Mercury to Pounds per Square Inch?
Engineers, mechanics, and scientists frequently need to convert pressure between Millimeters of Mercury and Pounds per Square Inch when working with different measurement standards. Tire pressure, blood pressure readings, weather barometric measurements, and industrial process specifications may all use different pressure units depending on the region or discipline. Reliable conversion prevents equipment misuse and ensures safety.
Frequently Asked Questions
How do I convert Millimeters of Mercury to Pounds per Square Inch?
A unit of pressure historically defined as the pressure exerted by a column of mercury exactly 1 millimeter tall at the standard acceleration of gravity (9. To convert Millimeters of Mercury to Pounds per Square Inch, multiply by 0.0193367. For example, 25 mmHg equals 0.483418 psi.
How many Pounds per Square Inch are in 1 Millimeters of Mercury?
There are 0.0193367 Pounds per Square Inch in 1 Millimeters of Mercury.
How many Millimeters of Mercury are in 1 Pound per Square Inch?
There are 51.7151 Millimeters of Mercury in 1 Pound per Square Inch.
What is the formula for Millimeters of Mercury to Pound per Square Inch conversion?
The formula is: multiply by 0.0193367. This means 1 mmHg = 0.0193367 psi.
Is a Millimeters of Mercury bigger than a Pound per Square Inch?
Yes. One Millimeters of Mercury is larger than one Pound per Square Inch because 1 mmHg equals 0.0193367 psi, which is less than 1.
When do you need to convert between Millimeters of Mercury and Pounds per Square Inch?
An imperial unit of pressure equal to one pound-force applied over one square inch (exactly 6,894. Millimeters of Mercury and Pound per Square Inch are both pressure units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.