Convert psi to millimeters of mercury
Converting psi to millimeters of mercury is a common pressure task, whether you are checking a recipe, a spec sheet, a travel distance or a homework problem. Since 1 psi equals 51.7149 mmHg, the math is a single multiplication — and this page does it for you instantly, with the formula, a table of common values and answers to the questions people ask most.
Exact factor
How to convert psi to millimeters of mercury
To convert psi to millimeters of mercury, multiply the number of psi by 51.7149. For example, 10 psi × 51.7149 = 517.149 mmHg.
mmHg = psi × 51.7149
- Write down the value in psi you want to convert.
- Multiply it by 51.7149 (the exact psi→mmHg factor).
- The result is your value in millimeters of mercury. Check it below with the converter or the table.
Conversion table
Common values of psi and their equivalents in millimeters of mercury:
| psi | mmHg |
|---|---|
| 1 | 51.7149 |
| 2 | 103.43 |
| 3 | 155.145 |
| 4 | 206.86 |
| 5 | 258.575 |
| 10 | 517.149 |
| 20 | 1,034.3 |
| 25 | 1,292.87 |
| 50 | 2,585.75 |
| 100 | 5,171.49 |
| 250 | 12,928.7 |
| 500 | 25,857.5 |
About these units
PSI (psi). Pounds per square inch (psi) is the US customary pressure unit, one pound-force applied to one square inch. Tire gauges, compressed air and hydraulics in the US are measured in psi.
Millimeter of Mercury (mmHg). A millimeter of mercury is the pressure exerted by a one-millimeter column of mercury, about 133.32 pascals. Blood pressure and vacuum measurements are still quoted in mmHg.
Frequently asked questions
How do I convert psi to millimeters of mercury?
To convert psi to millimeters of mercury, multiply the number of psi by 51.7149. For example, 10 psi × 51.7149 = 517.149 mmHg. Or skip the math: type the value into the converter at the top of this page and the result updates instantly.
How many millimeters of mercury are in 1 psi?
1 psi = 51.7149 mmHg. That is the fixed relationship used by this converter and by international standards.
How many psi are in 1 millimeter of mercury?
1 mmHg = 0.0193368 psi. If you are converting in the opposite direction, use our Millimeter of Mercury to PSI converter for the dedicated table and FAQ.
Is the psi to millimeters of mercury conversion exact?
Yes. Both units are defined by international agreement, so the factor of 51.7149 is exact. Displayed results are rounded to 6 significant digits only for readability.
What is psi used for?
Pounds per square inch (psi) is the US customary pressure unit, one pound-force applied to one square inch. Tire gauges, compressed air and hydraulics in the US are measured in psi.