Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Pounds per square inch to Millimetres of mercury
Convert psi to mmHg instantly, then review the formula, assumptions, and rounding guidance.
Pressure & stressInstant result
Decimals
Formula result = input × 6894.757293 ÷ 133.3223874. 1 psi = 51.7149 mmHg
Common examples
One value, several units
Pascals6,894.7573 Pa
Kilopascals6.8948 kPa
Megapascals0.0069 MPa
Bar0.0689 bar
Atmospheres0.068 atm
Millimetres of mercury51.7149 mmHg
Conversion table
| psi | mmHg |
|---|---|
| 1 psi | 51.7149 mmHg |
| 2 psi | 103.4299 mmHg |
| 5 psi | 258.5746 mmHg |
| 10 psi | 517.1493 mmHg |
| 25 psi | 1,292.8731 mmHg |
| 50 psi | 2,585.7463 mmHg |
| 100 psi | 5,171.4925 mmHg |
Conversion chart
1 psi51.7149 mmHg
5 psi258.5746 mmHg
10 psi517.1493 mmHg
25 psi1,292.8731 mmHg
50 psi2,585.7463 mmHg
Worked example
Standard atmosphere is 101,325 pascals.
Unit definition
Pounds per square inch (psi) One pounds per square inch equals 6,894.757293 pascal.
Unit history
Pounds per square inch is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert psi to pascal.
3. Convert the base value to mmHg and apply your display precision.
Understand the result before using it
Pounds per square inch to Millimetres of mercury converts a value measured in Pounds per square inch (psi) into the equivalent value in Millimetres of mercury (mmHg). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 6894.757293 ÷ 133.3223874
Assumptions
- Pounds per square inch and Millimetres of mercury represent the same pressure & stress quantity.
- The input is expressed in psi; the output is expressed in mmHg.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 psi = 51.7149252084 mmHg. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a psi measurement in a document that expects mmHg.
- Compare a pounds per square inch value with a value reported in millimetres of mercury.
- Check the psi-to-mmHg arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- Do not confuse psi with another unit that has a similar name or symbol.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Pounds per square inch to Millimetres of mercury?
result = input × 6894.757293 ÷ 133.3223874 Using the displayed relationship, 1 psi equals 51.7149252084 mmHg.
How many Millimetres of mercury are in one Pounds per square inch?
One Pounds per square inch is 51.7149252084 Millimetres of mercury. The displayed digits may be rounded.
Can I reverse the psi to mmHg conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts mmHg back to psi.
Is the Pounds per square inch to Millimetres of mercury result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.