PSI to mmHg Converter
Convert pounds per square inch to millimetres of mercury — multiply by 51.715. Results update as you type; exact factors shown.
One pound per square inch is 51.7149 millimetre of mercurys — see the exact factor, not a rounded rule of thumb.
How the psi to mmhg converter works
Pressures convert through the pascal (1 N/m²). One bar is exactly 100 kPa; a standard atmosphere is exactly 101.325 kPa; 1 psi is 6.894757 kPa (a pound-force on a square inch); 1 mmHg is 133.322 Pa by the conventional definition.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common pressure conversions
| From | To | Units |
|---|---|---|
| 0.5 psi | 25.8575 mmHg | pounds per square inch to millimetre of mercurys |
| 1 psi | 51.7149 mmHg | pound per square inch to millimetre of mercurys |
| 2 psi | 103.4299 mmHg | pounds per square inch to millimetre of mercurys |
| 2.32 psi | 119.9786 mmHg | pounds per square inch to millimetre of mercurys |
| 5 psi | 258.5746 mmHg | pounds per square inch to millimetre of mercurys |
| 10 psi | 517.1493 mmHg | pounds per square inch to millimetre of mercurys |
| 14.696 psi | 760.0025 mmHg | pounds per square inch to millimetre of mercurys |
| 20 psi | 1,034.2985 mmHg | pounds per square inch to millimetre of mercurys |
| 30 psi | 1,551.4478 mmHg | pounds per square inch to millimetre of mercurys |
| 50 psi | 2,585.7463 mmHg | pounds per square inch to millimetre of mercurys |
| 100 psi | 5,171.4925 mmHg | pounds per square inch to millimetre of mercurys |
| 500 psi | 25,857.4626 mmHg | pounds per square inch to millimetre of mercurys |
Units in this converter and their exact factors
| Unit | Symbol | One unit in pascals |
|---|---|---|
| pascal | Pa | 1 pascal |
| kilopascal | kPa | 1,000 pascal |
| megapascal | MPa | 1,000,000 pascal |
| bar | bar | 100,000 pascal |
| millibar (hectopascal) | mbar | 100 pascal |
| standard atmosphere | atm | 101,325 pascal |
| pound per square inch | psi | 6,894.757293168 pascal |
| millimetre of mercury | mmHg | 133.322387415 pascal |
| inch of mercury | inHg | 3,386.389 pascal |
FAQFrequently asked questions about pressure conversion
How many mmHg in a psi?
51.715.
What is 14.696 psi?
760 mmHg, one atmosphere.
Why convert?
Because medical and vacuum instruments read mmHg while industrial gauges read psi.
What is a blood pressure in psi?
120/80 mmHg is about 2.3/1.5 psi — small pressures by industrial standards.
What is full vacuum?
760 mmHg below atmospheric, or 14.7 psi.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.