How to convert PSI to mmHg
To convert PSI to mmHg, multiply by 51.7149252039. Pressure conversions are used for tire inflation, weather, scuba diving, hydraulics and medical devices.

PSI to mmHg conversion table
| PSI (psi) | mmHg (mmHg) |
|---|---|
| 0.1 psi | 5.17149252039 mmHg |
| 0.5 psi | 25.8574626019 mmHg |
| 1 psi | 51.7149252039 mmHg |
| 2 psi | 103.429850408 mmHg |
| 3 psi | 155.144775612 mmHg |
| 4 psi | 206.859700815 mmHg |
| 5 psi | 258.574626019 mmHg |
| 10 psi | 517.149252039 mmHg |
| 20 psi | 1,034.29850408 mmHg |
| 25 psi | 1,292.8731301 mmHg |
| 50 psi | 2,585.74626019 mmHg |
| 100 psi | 5,171.49252039 mmHg |
| 500 psi | 25,857.4626019 mmHg |
| 1,000 psi | 51,714.9252039 mmHg |
About the units
PSI (psi)
Pounds per square inch is the US unit for tire, air compressor and hydraulic pressure.
mmHg (mmHg)
Millimeters of mercury are used for blood pressure and barometric readings (1 mmHg ≈ 133.322 Pa).
How to use this converter
- Type the number of PSI (psi) in the input box.
- The result in mmHg appears instantly — no button needed.
- See the same value in every other pressure unit just below.
- Use “Swap units” to convert mmHg back to PSI.
Tips for better results
- Double-check which system a unit belongs to (for example US vs UK gallons).
- Use the swap button to convert in the opposite direction instantly.
- Bookmark the conversions you use most — each pair has its own page.
Frequently asked questions
How many mmHg are in one psi?
One psi equals 51.7149252039 mmHg. 51.7149252039 is the exact factor used by this converter.
How do I convert PSI to mmHg?
Multiply the value in PSI by 51.7149252039. To go the other way, multiply mmHg by 0.0193367774595.
What is 10 psi in mmHg?
10 psi = 517.149252039 mmHg. Also, 5 psi = 258.574626019 mmHg and 100 psi = 5,171.49252039 mmHg.
What is the difference between a psi and a mmhg?
Pounds per square inch is the US unit for tire, air compressor and hydraulic pressure. Millimeters of mercury are used for blood pressure and barometric readings (1 mmHg ≈ 133.322 Pa).
Is this tool free and private?
Yes — the PSI to mmHg is completely free with no sign-up, and it runs entirely in your browser, so the values you enter are never uploaded to our servers.
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