Millimetres of mercury to pounds per square inch
Multiply millimetres of mercury by 0.0193368 to get pounds per square inch.
200 mmHg = 3.8674 psi
How to convert millimetres of mercury to pounds per square inch
The pound per square inch is pounds-force per square inch, exactly 6894.757293168 pascals. The millimetre of mercury is the conventional millimetre of mercury, exactly 101325/760 pascals (about 133.322 Pa), equal to the torr.
Worked example — 200 mmHg: 200 × 0.0193368 = 3.8674 psi.
Millimetres of mercury to pounds per square inch table
| Millimetres of mercury | Pounds per square inch |
|---|---|
| 1 mmHg | 0.0193368 psi |
| 10 mmHg | 0.193368 psi |
| 50 mmHg | 0.966839 psi |
| 100 mmHg | 1.9337 psi |
| 200 mmHg | 3.8674 psi |
| 400 mmHg | 7.7347 psi |
| 600 mmHg | 11.6021 psi |
| 760 mmHg | 14.6959 psi |
| 1,000 mmHg | 19.3368 psi |
Reverse and related
About millimetres of mercury and pounds per square inch
Millimetre of mercury (mmHg)
1 mmHg = 0.0193368 psiDefinition. The conventional millimetre of mercury, exactly 101325/760 pascals (about 133.322 Pa), equal to the torr
History and origin
The millimetre of mercury comes from mercury barometers, where pressure was read as the height of a mercury column. It is now fixed conventionally as one 760th of a standard atmosphere, essentially equal to the torr.
Current use
mmHg is the standard unit for blood pressure — a reading of 120/80 mmHg — and for measuring vacuums.
Source: NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi)
Pound per square inch (psi)
1 psi = 51.7149 mmHgDefinition. Pounds-force per square inch, exactly 6894.757293168 pascals
History and origin
The pound per square inch comes from the imperial system, expressing pressure as pounds-force spread over a square inch. It equals about 6895 pascals.
Current use
Psi is the everyday pressure unit in the United States for tyre pressure, plumbing and compressed air.
Source: NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi)
Where people use this
Millimetres of mercury: blood pressure, vacuum measurement. Pounds per square inch: tyre pressure in the US, plumbing, compressed air. 760 mmHg is about 14.7 psi.
Every value is carried to full double precision; the display is rounded.
Both units are defined in NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi).
Questions people ask
How many psi is 760 mmHg?
760 mmHg (one atmosphere) is about 14.7 psi.
How many psi in a mmHg?
One mmHg is about 0.0193 psi.
How many mmHg is 1 psi?
One psi is about 51.7 mmHg.