Psi to Millimeters Of Mercury
Convert psi to millimeters of mercury instantly — one pound per square inch is 51.7149 millimeters of mercury.
| Psi | Millimeters Of Mercury |
|---|---|
| 1 psi | 51.714925 mmHg |
| 2 psi | 103.42985 mmHg |
| 3 psi | 155.144776 mmHg |
| 5 psi | 258.574626 mmHg |
| 10 psi | 517.149252 mmHg |
| 25 psi | 1292.87313 mmHg |
| 50 psi | 2585.74626 mmHg |
| 100 psi | 5171.49252 mmHg |
How to use
- Enter a value in the Psi field.
- The Millimeters Of Mercury figure appears immediately — no button to press.
- Typing in the Millimeters Of Mercury field converts back to Psi the same way.
- Use the reference table for the values that come up most often.
Psi to Millimeters Of Mercury formula
To convert psi to millimeters of mercury, multiply by 51.7149252.
mmHg = psi × 51.7149252
Why this factor: the pound per square inch and the millimeter of mercury are both defined against the pascal, so dividing one definition by the other gives 51.7149252 directly. Both definitions are set out in full below.
To go the other way, divide by 51.7149252 — or use the Millimeters Of Mercury to Psi converter, which is the same calculation reversed.
Worked example
Start with 760 psi. Multiply by 51.7149252 to get 39303.343155 mmHg.
760 psi × 51.7149252 = 39303.343155 mmHg
The converter above does this for any value you type, in either direction.
What is a pound per square inch?
Pounds per square inch is the standard pressure unit in the United States.
Definition: One pound-force per square inch, which is about 6,894.757 pascals.
Where it is used: US tire pressure, compressed air and hydraulic systems, and plumbing water pressure.
What is a millimeter of mercury?
A millimeter of mercury is the pressure exerted by a 1 mm column of mercury, still standard in medicine.
Definition: Defined as exactly 133.322387415 pascals.
Where it is used: Blood pressure readings, intraocular pressure, and respiratory gas pressures.
Worth knowing: Blood pressure is universally reported in mmHg even in fully metric countries — one of the most durable legacy units in medicine.
Psi vs Millimeters Of Mercury
The pound per square inch is a US customary unit while the millimeter of mercury is a specialized unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many millimeters of mercury are in a pound per square inch?
One pound per square inch equals 51.7149252 millimeters of mercury.
What is the formula to convert psi to millimeters of mercury?
Multiply the number of psi by 51.7149252. To reverse it, divide by 51.7149252 instead.
How do I convert millimeters of mercury back to psi?
Divide by 51.7149252, which is the same as multiplying by 0.0193367775.
How many millimeters of mercury are in 10 psi?
10 psi works out to 517.149252 mmHg.
Is there anything to watch out for with millimeters of mercury?
Blood pressure is universally reported in mmHg even in fully metric countries — one of the most durable legacy units in medicine.
How is the pound per square inch defined?
One pound-force per square inch, which is about 6,894.757 pascals.